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• Suspended Laptop Cannot Wake Up - Ubuntu

  - by Zack

  I've got an ASUS G73JH, and whenever I suspend it or hibernate it, it will not wake up. The screen stays backlight but is black. The fan remains running, however the HDD does not, not disk activity is noticeable (audibly (It's not a SSD)). I can't: Awaken it with the keyboard Awaken it with the mouse Soft power-off by pressing the power button Change virtual screens by pressing Ctrl-Alt-# Restart X by pressing Ctrl-Alt-Backspace I have to hold down the power button and shut it down that way, and this seems a little unreasonable. Is there a place I could look for more detail as to what's causing this? Is there a known quick-fix to this issue? Nothing is logged as happening when the system is in "suspend" mode. Here's what happened immediately before and after the suspend "happened," note the time gap: May 4 17:46:13 tofu NetworkManager: <info> (eth0): carrier now OFF (device state 1) May 4 17:48:57 tofu kernel: imklog 4.2.0, log source = /proc/kmsg started. This one's kinda long, here's what happened immediately before the suspend, I'm not sure if it'll help but if you can find a use for it: May 4 17:46:10 tofu anacron[3353]: Anacron 2.3 started on 2010-05-04 May 4 17:46:10 tofu anacron[3353]: Normal exit (0 jobs run) May 4 17:46:10 tofu kernel: [ 2241.775927] CPU0 attaching NULL sched-domain. May 4 17:46:10 tofu kernel: [ 2241.775958] CPU1 attaching NULL sched-domain. May 4 17:46:10 tofu kernel: [ 2241.775987] CPU2 attaching NULL sched-domain. May 4 17:46:10 tofu kernel: [ 2241.776138] CPU3 attaching NULL sched-domain. May 4 17:46:10 tofu kernel: [ 2241.776168] CPU4 attaching NULL sched-domain. May 4 17:46:10 tofu kernel: [ 2241.776197] CPU5 attaching NULL sched-domain. May 4 17:46:10 tofu kernel: [ 2241.776200] CPU6 attaching NULL sched-domain. May 4 17:46:10 tofu kernel: [ 2241.776229] CPU7 attaching NULL sched-domain. May 4 17:46:10 tofu kernel: [ 2241.919611] CPU0 attaching sched-domain: May 4 17:46:10 tofu kernel: [ 2241.919668] domain 0: span 0,4 level SIBLING May 4 17:46:10 tofu kernel: [ 2241.919699] groups: 0 (cpu_power = 589) 4 (cpu_power = 589) May 4 17:46:10 tofu kernel: [ 2241.919733] domain 1: span 0-7 level MC May 4 17:46:10 tofu kernel: [ 2241.919762] groups: 0,4 (cpu_power = 1178) 1,5 (cpu_power = 1178) 2,6 (cpu_power = 1178) 3,7 (cpu_power = 1178) May 4 17:46:10 tofu kernel: [ 2241.919850] CPU1 attaching sched-domain: May 4 17:46:10 tofu kernel: [ 2241.919852] domain 0: span 1,5 level SIBLING May 4 17:46:10 tofu kernel: [ 2241.919881] groups: 1 (cpu_power = 589) 5 (cpu_power = 589) May 4 17:46:10 tofu kernel: [ 2241.919912] domain 1: span 0-7 level MC May 4 17:46:10 tofu kernel: [ 2241.919915] groups: 1,5 (cpu_power = 1178) 2,6 (cpu_power = 1178) 3,7 (cpu_power = 1178) 0,4 (cpu_power = 1178) May 4 17:46:10 tofu kernel: [ 2241.920003] CPU2 attaching sched-domain: May 4 17:46:10 tofu kernel: [ 2241.920005] domain 0: span 2,6 level SIBLING May 4 17:46:10 tofu kernel: [ 2241.920033] groups: 2 (cpu_power = 589) 6 (cpu_power = 589) May 4 17:46:10 tofu kernel: [ 2241.920065] domain 1: span 0-7 level MC May 4 17:46:10 tofu kernel: [ 2241.920093] groups: 2,6 (cpu_power = 1178) 3,7 (cpu_power = 1178) 0,4 (cpu_power = 1178) 1,5 (cpu_power = 1178) May 4 17:46:10 tofu kernel: [ 2241.920155] CPU3 attaching sched-domain: May 4 17:46:10 tofu kernel: [ 2241.920157] domain 0: span 3,7 level SIBLING May 4 17:46:10 tofu kernel: [ 2241.920185] groups: 3 (cpu_power = 589) 7 (cpu_power = 589) May 4 17:46:10 tofu kernel: [ 2241.920217] domain 1: span 0-7 level MC May 4 17:46:10 tofu kernel: [ 2241.920245] groups: 3,7 (cpu_power = 1178) 0,4 (cpu_power = 1178) 1,5 (cpu_power = 1178) 2,6 (cpu_power = 1178) May 4 17:46:10 tofu kernel: [ 2241.920307] CPU4 attaching sched-domain: May 4 17:46:10 tofu kernel: [ 2241.920335] domain 0: span 0,4 level SIBLING May 4 17:46:10 tofu kernel: [ 2241.920337] groups: 4 (cpu_power = 589) 0 (cpu_power = 589) May 4 17:46:10 tofu kernel: [ 2241.920368] domain 1: span 0-7 level MC May 4 17:46:10 tofu kernel: [ 2241.920397] groups: 0,4 (cpu_power = 1178) 1,5 (cpu_power = 1178) 2,6 (cpu_power = 1178) 3,7 (cpu_power = 1178) May 4 17:46:10 tofu kernel: [ 2241.920459] CPU5 attaching sched-domain: May 4 17:46:10 tofu kernel: [ 2241.920487] domain 0: span 1,5 level SIBLING May 4 17:46:10 tofu kernel: [ 2241.920489] groups: 5 (cpu_power = 589) 1 (cpu_power = 589) May 4 17:46:10 tofu kernel: [ 2241.920520] domain 1: span 0-7 level MC May 4 17:46:10 tofu kernel: [ 2241.920549] groups: 1,5 (cpu_power = 1178) 2,6 (cpu_power = 1178) 3,7 (cpu_power = 1178) 0,4 (cpu_power = 1178) May 4 17:46:10 tofu kernel: [ 2241.920611] CPU6 attaching sched-domain: May 4 17:46:10 tofu kernel: [ 2241.920639] domain 0: span 2,6 level SIBLING May 4 17:46:10 tofu kernel: [ 2241.920641] groups: 6 (cpu_power = 589) 2 (cpu_power = 589) May 4 17:46:10 tofu kernel: [ 2241.920699] domain 1: span 0-7 level MC May 4 17:46:10 tofu kernel: [ 2241.920701] groups: 2,6 (cpu_power = 1178) 3,7 (cpu_power = 1178) 0,4 (cpu_power = 1178) 1,5 (cpu_power = 1178) May 4 17:46:10 tofu kernel: [ 2241.920762] CPU7 attaching sched-domain: May 4 17:46:10 tofu kernel: [ 2241.920791] domain 0: span 3,7 level SIBLING May 4 17:46:10 tofu kernel: [ 2241.920793] groups: 7 (cpu_power = 589) 3 (cpu_power = 589) May 4 17:46:10 tofu kernel: [ 2241.920851] domain 1: span 0-7 level MC May 4 17:46:10 tofu kernel: [ 2241.920853] groups: 3,7 (cpu_power = 1178) 0,4 (cpu_power = 1178) 1,5 (cpu_power = 1178) 2,6 (cpu_power = 1178) May 4 17:46:12 tofu NetworkManager: <info> Sleeping... May 4 17:46:12 tofu NetworkManager: <info> (wlan0): now unmanaged May 4 17:46:12 tofu NetworkManager: <info> (wlan0): device state change: 8 -> 1 (reason 37) May 4 17:46:12 tofu NetworkManager: <info> (wlan0): deactivating device (reason: 37). May 4 17:46:12 tofu NetworkManager: <info> (wlan0): canceled DHCP transaction, dhcp client pid 1984 May 4 17:46:12 tofu kernel: [ 2244.084515] wlan0: deauthenticating from 68:7f:74:23:02:ae by local choice (reason=3) May 4 17:46:12 tofu avahi-daemon[1176]: Withdrawing address record for 192.168.1.2 on wlan0. May 4 17:46:12 tofu avahi-daemon[1176]: Leaving mDNS multicast group on interface wlan0.IPv4 with address 192.168.1.2. May 4 17:46:12 tofu avahi-daemon[1176]: Interface wlan0.IPv4 no longer relevant for mDNS. May 4 17:46:12 tofu NetworkManager: <info> Policy set 'Auto eth0' (eth0) as default for routing and DNS. May 4 17:46:12 tofu NetworkManager: <info> (wlan0): cleaning up... May 4 17:46:12 tofu NetworkManager: <info> (wlan0): taking down device. May 4 17:46:12 tofu avahi-daemon[1176]: Withdrawing address record for 2002:4c6e:638a:0:1e4b:d6ff:fe78:951d on wlan0. May 4 17:46:12 tofu wpa_supplicant[1212]: CTRL-EVENT-DISCONNECTED - Disconnect event - remove keys May 4 17:46:13 tofu NetworkManager: <info> (eth0): now unmanaged May 4 17:46:13 tofu NetworkManager: <info> (eth0): device state change: 8 -> 1 (reason 37) May 4 17:46:13 tofu NetworkManager: <info> (eth0): deactivating device (reason: 37). May 4 17:46:13 tofu NetworkManager: <info> (eth0): canceled DHCP transaction, dhcp client pid 1559 May 4 17:46:13 tofu NetworkManager: <WARN> check_one_route(): (eth0) error -34 returned from rtnl_route_del(): Sucess#012 May 4 17:46:13 tofu avahi-daemon[1176]: Withdrawing address record for 192.168.1.3 on eth0. May 4 17:46:13 tofu avahi-daemon[1176]: Leaving mDNS multicast group on interface eth0.IPv4 with address 192.168.1.3. May 4 17:46:13 tofu avahi-daemon[1176]: Interface eth0.IPv4 no longer relevant for mDNS. May 4 17:46:13 tofu NetworkManager: <info> (eth0): cleaning up... May 4 17:46:13 tofu NetworkManager: <info> (eth0): taking down device. May 4 17:46:13 tofu avahi-daemon[1176]: Withdrawing address record for 2002:4c6e:638a:0:4a5b:39ff:fe0b:325d on eth0. May 4 17:46:13 tofu NetworkManager: <info> (eth0): carrier now OFF (device state 1)

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• sp_send_dbmail attach files stored as varbinary in database

  - by Mindstorm Interactive

  I have a two part question relating to sending query results as attachments using sp_send_dbmail. Problem 1: Only basic .txt files will open. Any other format like .pdf or .jpg are corrupted. Problem 2: When attempting to send multiple attachments, I receive one file with all file names glued together. I'm running SQL Server 2005 and I have a table storing uploaded documents: CREATE TABLE [dbo].[EmailAttachment]( [EmailAttachmentID] [int] IDENTITY(1,1) NOT NULL, [MassEmailID] [int] NULL, -- foreign key [FileData] [varbinary](max) NOT NULL, [FileName] [varchar](100) NOT NULL, [MimeType] [varchar](100) NOT NULL I also have a MassEmail table with standard email stuff. Here is the SQL Send Mail script. For brevity, I've excluded declare statements. while ( (select count(MassEmailID) from MassEmail where status = 20 )>0) begin select @MassEmailID = Min(MassEmailID) from MassEmail where status = 20 select @Subject = [Subject] from MassEmail where MassEmailID = @MassEmailID select @Body = Body from MassEmail where MassEmailID = @MassEmailID set @query = 'set nocount on; select cast(FileData as varchar(max)) from Mydatabase.dbo.EmailAttachment where MassEmailID = '+ CAST(@MassEmailID as varchar(100)) select @filename = '' select @filename = COALESCE(@filename+ ',', '') +FileName from EmailAttachment where MassEmailID = @MassEmailID exec msdb.dbo.sp_send_dbmail @profile_name = 'MASS_EMAIL', @recipients = '[email protected]', @subject = @Subject, @body =@Body, @body_format ='HTML', @query = @query, @query_attachment_filename = @filename, @attach_query_result_as_file = 1, @query_result_separator = '; ', @query_no_truncate = 1, @query_result_header = 0; update MassEmailset status= 30,SendDate = GetDate() where MassEmailID = @MassEmailID end I am able to successfully read files from the database so I know the binary data is not corrupted. .txt files only read when I cast FilaData to varchar. But clearly original headers are lost. It's also worth noting that attachment file sizes are different than the original files. That is most likely due to improper encoding as well. So I'm hoping there's a way to create file headers using the stored mimetype, or some way to include file headers in the binary data? I'm also not confident in the values of the last few parameters, and I know coalesce is not quite right, because it prepends the first file name with a comma. But good documentation is nearly impossible to find. Please help!

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• Serializing object with no namespaces using DataContractSerializer

  - by Yurik

  How do I remove XML namespaces from an object's XML representation serialized using DataContractSerializer? That object needs to be serialized to a very simple output XML. Latest & greatest - using .Net 4 beta 2 The object will never need to be deserialized. XML should not have any xmlns:... namespace refs Any subtypes of Exception and ISubObject need to be supported. It will be very difficult to change the original object. Object: [Serializable] class MyObj { string str; Exception ex; ISubObject subobj; } Need to serialize into: <xml> <str>...</str> <ex i:nil="true" /> <subobj i:type="Abc"> <AbcProp1>...</AbcProp1> <AbcProp2>...</AbcProp2> </subobj> </xml> I used this code: private static string ObjectToXmlString(object obj) { if (obj == null) throw new ArgumentNullException("obj"); var serializer = new DataContractSerializer( obj.GetType(), null, Int32.MaxValue, false, false, null, new AllowAllContractResolver()); var sb = new StringBuilder(); using (var xw = XmlWriter.Create(sb, new XmlWriterSettings { OmitXmlDeclaration = true, NamespaceHandling = NamespaceHandling.OmitDuplicates, Indent = true })) { serializer.WriteObject(xw, obj); xw.Flush(); return sb.ToString(); } } From this article I adopted a DataContractResolver so that no subtypes have to be declared: public class AllowAllContractResolver : DataContractResolver { public override bool TryResolveType(Type dataContractType, Type declaredType, DataContractResolver knownTypeResolver, out XmlDictionaryString typeName, out XmlDictionaryString typeNamespace) { if (!knownTypeResolver.TryResolveType(dataContractType, declaredType, null, out typeName, out typeNamespace)) { var dictionary = new XmlDictionary(); typeName = dictionary.Add(dataContractType.FullName); typeNamespace = dictionary.Add(dataContractType.Assembly.FullName); } return true; } public override Type ResolveName(string typeName, string typeNamespace, Type declaredType, DataContractResolver knownTypeResolver) { return knownTypeResolver.ResolveName(typeName, typeNamespace, declaredType, null) ?? Type.GetType(typeName + ", " + typeNamespace); } }

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• Paste Functionality for WPF DataGrid with DataGridTemplateColumns

  - by zmang

  Hi. I recently started using the WPF Datagrid with DataGridTemplateColumns containing the WPF AutoCompleteBox, but I'm finding trouble in implementing Clipboard.Paste functionality for these DataGridTemplateColumns. I've managed to get Clipboard.Paste working with built-in DataGridColumns via Vishal's guide here, but it doesn't work with DataGridTemplateColumns. Delving into the OnPastingCellClipboardContent method in the DataGridColumn class, it appears that fe.GetBindingExpression(CellValueProperty) is returning null rather than the required BindingExpression. Can anyone point me to the right direction? public virtual void OnPastingCellClipboardContent(object item, object cellContent) { BindingBase binding = ClipboardContentBinding; if (binding != null) { // Raise the event to give a chance for external listeners to modify the cell content // before it gets stored into the cell if (PastingCellClipboardContent != null) { DataGridCellClipboardEventArgs args = new DataGridCellClipboardEventArgs(item, this, cellContent); PastingCellClipboardContent(this, args); cellContent = args.Content; } // Event handlers can cancel Paste of a cell by setting its content to null if (cellContent != null) { FrameworkElement fe = new FrameworkElement(); fe.DataContext = item; fe.SetBinding(CellValueProperty, binding); fe.SetValue(CellValueProperty, cellContent); BindingExpression be = fe.GetBindingExpression(CellValueProperty); be.UpdateSource(); } } Thanks!

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• java.lang.ClassCastException: java.lang.Integer cannot be cast to java.util.HashMap

  - by kongkea

  I've got this Error When I click listview to show full image size. how can i solve it? Error 11-20 10:27:47.039: D/AndroidRuntime(5078): Shutting down VM 11-20 10:27:47.039: W/dalvikvm(5078): threadid=1: thread exiting with uncaught exception (group=0x40c061f8) 11-20 10:27:47.047: E/AndroidRuntime(5078): FATAL EXCEPTION: main 11-20 10:27:47.047: E/AndroidRuntime(5078): java.lang.ClassCastException: java.lang.Integer cannot be cast to java.util.HashMap 11-20 10:27:47.047: E/AndroidRuntime(5078): at com.example.mylistview.MainActivity$1.onItemClick(MainActivity.java:103) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.widget.AdapterView.performItemClick(AdapterView.java:292) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.widget.AbsListView.performItemClick(AbsListView.java:1173) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.widget.AbsListView$PerformClick.run(AbsListView.java:2701) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.widget.AbsListView$1.run(AbsListView.java:3453) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.os.Handler.handleCallback(Handler.java:605) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.os.Handler.dispatchMessage(Handler.java:92) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.os.Looper.loop(Looper.java:137) 11-20 10:27:47.047: E/AndroidRuntime(5078): at android.app.ActivityThread.main(ActivityThread.java:4514) 11-20 10:27:47.047: E/AndroidRuntime(5078): at java.lang.reflect.Method.invokeNative(Native Method) 11-20 10:27:47.047: E/AndroidRuntime(5078): at java.lang.reflect.Method.invoke(Method.java:511) 11-20 10:27:47.047: E/AndroidRuntime(5078): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:790) 11-20 10:27:47.047: E/AndroidRuntime(5078): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557) 11-20 10:27:47.047: E/AndroidRuntime(5078): at dalvik.system.NativeStart.main(Native Method) MainActivity public class MainActivity extends Activity { public static final int DIALOG_DOWNLOAD_JSON_PROGRESS = 0; private ProgressDialog mProgressDialog; ArrayList<HashMap<String, Object>> MyArrList; @SuppressLint("NewApi") @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // Permission StrictMode if (android.os.Build.VERSION.SDK_INT > 9) { StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build(); StrictMode.setThreadPolicy(policy); } // Download JSON File new DownloadJSONFileAsync().execute(); } @Override protected Dialog onCreateDialog(int id) { switch (id) { case DIALOG_DOWNLOAD_JSON_PROGRESS: mProgressDialog = new ProgressDialog(this); mProgressDialog.setMessage("Downloading....."); mProgressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER); mProgressDialog.setCancelable(true); mProgressDialog.show(); return mProgressDialog; default: return null; } } // Show All Content public void ShowAllContent() { // listView1 final ListView lstView1 = (ListView)findViewById(R.id.listView1); lstView1.setAdapter(new ImageAdapter(MainActivity.this,MyArrList)); lstView1.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View v, int position, long id) { HashMap<String, Object> hm = (HashMap<String, Object>) lstView1.getAdapter().getItem(position); String imagePath = (String) hm.get("photo"); Intent i = new Intent(MainActivity.this,FullImageActivity.class); i.putExtra("fullImage", imagePath); startActivity(i); } }); } public class ImageAdapter extends BaseAdapter { private Context context; private ArrayList<HashMap<String, Object>> MyArr = new ArrayList<HashMap<String, Object>>(); public ImageAdapter(Context c, ArrayList<HashMap<String, Object>> myArrList) { // TODO Auto-generated method stub context = c; MyArr = myArrList; } public int getCount() { // TODO Auto-generated method stub return MyArr.size(); } public Object getItem(int position) { // TODO Auto-generated method stub return position; } public long getItemId(int position) { // TODO Auto-generated method stub return position; } public View getView(int position, View convertView, ViewGroup parent) { // TODO Auto-generated method stub LayoutInflater inflater = (LayoutInflater) context .getSystemService(Context.LAYOUT_INFLATER_SERVICE); if (convertView == null) { convertView = inflater.inflate(R.layout.activity_column, null); } // ColImage ImageView imageView = (ImageView) convertView.findViewById(R.id.ColImgPath); imageView.getLayoutParams().height = 80; imageView.getLayoutParams().width = 80; imageView.setPadding(5, 5, 5, 5); imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); try { imageView.setImageBitmap((Bitmap)MyArr.get(position).get("ImageThumBitmap")); } catch (Exception e) { // When Error imageView.setImageResource(android.R.drawable.ic_menu_report_image); } // ColImgID TextView txtImgID = (TextView) convertView.findViewById(R.id.ColImgID); txtImgID.setPadding(10, 0, 0, 0); txtImgID.setText("ID : " + MyArr.get(position).get("id").toString()); // ColImgName TextView txtPicName = (TextView) convertView.findViewById(R.id.ColImgName); txtPicName.setPadding(50, 0, 0, 0); txtPicName.setText("Name : " + MyArr.get(position).get("first_name").toString()); return convertView; } } // Download JSON in Background public class DownloadJSONFileAsync extends AsyncTask<String, Void, Void> { protected void onPreExecute() { super.onPreExecute(); showDialog(DIALOG_DOWNLOAD_JSON_PROGRESS); } @Override protected Void doInBackground(String... params) { // TODO Auto-generated method stub String url = "http://192.168.10.104/adchara1/"; JSONArray data; try { data = new JSONArray(getJSONUrl(url)); MyArrList = new ArrayList<HashMap<String, Object>>(); HashMap<String, Object> map; for(int i = 0; i < data.length(); i++){ JSONObject c = data.getJSONObject(i); map = new HashMap<String, Object>(); map.put("id", (String)c.getString("id")); map.put("first_name", (String)c.getString("first_name")); // Thumbnail Get ImageBitmap To Object map.put("photo", (String)c.getString("photo")); map.put("ImageThumBitmap", (Bitmap)loadBitmap(c.getString("photo"))); // Full (for View Popup) map.put("frame", (String)c.getString("frame")); MyArrList.add(map); } } catch (JSONException e) { // TODO Auto-generated catch block e.printStackTrace(); } return null; } protected void onPostExecute(Void unused) { ShowAllContent(); // When Finish Show Content dismissDialog(DIALOG_DOWNLOAD_JSON_PROGRESS); removeDialog(DIALOG_DOWNLOAD_JSON_PROGRESS); } } /*** Get JSON Code from URL ***/ public String getJSONUrl(String url) { StringBuilder str = new StringBuilder(); HttpClient client = new DefaultHttpClient(); HttpGet httpGet = new HttpGet(url); try { HttpResponse response = client.execute(httpGet); StatusLine statusLine = response.getStatusLine(); int statusCode = statusLine.getStatusCode(); if (statusCode == 200) { // Download OK HttpEntity entity = response.getEntity(); InputStream content = entity.getContent(); BufferedReader reader = new BufferedReader(new InputStreamReader(content)); String line; while ((line = reader.readLine()) != null) { str.append(line); } } else { Log.e("Log", "Failed to download file.."); } } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return str.toString(); } /***** Get Image Resource from URL (Start) *****/ private static final String TAG = "Image"; private static final int IO_BUFFER_SIZE = 4 * 1024; public static Bitmap loadBitmap(String url) { Bitmap bitmap = null; InputStream in = null; BufferedOutputStream out = null; try { in = new BufferedInputStream(new URL(url).openStream(), IO_BUFFER_SIZE); final ByteArrayOutputStream dataStream = new ByteArrayOutputStream(); out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE); copy(in, out); out.flush(); final byte[] data = dataStream.toByteArray(); BitmapFactory.Options options = new BitmapFactory.Options(); //options.inSampleSize = 1; bitmap = BitmapFactory.decodeByteArray(data, 0, data.length,options); } catch (IOException e) { Log.e(TAG, "Could not load Bitmap from: " + url); } finally { closeStream(in); closeStream(out); } return bitmap; } private static void closeStream(Closeable stream) { if (stream != null) { try { stream.close(); } catch (IOException e) { android.util.Log.e(TAG, "Could not close stream", e); } } } private static void copy(InputStream in, OutputStream out) throws IOException { byte[] b = new byte[IO_BUFFER_SIZE]; int read; while ((read = in.read(b)) != -1) { out.write(b, 0, read); } } /***** Get Image Resource from URL (End) *****/ @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_main, menu); return true; } } FullImageActivity String imagePath = getIntent().getStringExtra("fullImage"); if(imagePath != null && !imagePath.isEmpty()){ File imageFile = new File(imagePath); if(imageFile.exists()){ Bitmap myBitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath()); ImageView iv = (ImageView) findViewById(R.id.fullimage); iv.setImageBitmap(myBitmap); } }

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• WPF: Asynchronous progress bar

  - by SumGuy

  I'm trying to create a progress bar that will work asynchronously to the main process. I'm created a new event and invoked it however everytime I then try to perform operations on the progress bar I recieve the following error: "The calling thread cannot access this object because a different thread owns it" The following code is an attempt to send an instance of the progress bar to the event as an object, it obviously failed but it gives you an idea of what the code looks like. private event EventHandler importing; void MdbDataImport_importing(object sender, EventArgs e) { ProgressBar pb = (ProgressBar)sender; while (true) { if (pb.Value >= 200) pb.Value = 0; pb.Value += 10; } } private void btnImport_Click(object sender, RoutedEventArgs e) { importing += new EventHandler(MdbDataImport_importing); IAsyncResult aResult = null; aResult = importing.BeginInvoke(pbDataImport, null, null, null); importing.EndInvoke(aResult); } Does anyone have ideas of how to do this. Thanks in advance SumGuy.

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• WinVerifyTrust API problem

  - by Shayan

  I'm using WinVerifyTrust API in windows XP and I don't want any kind of user interaction. But when I set the WTD_UI_NONE attribute, although it doesn't show any dialog boxes, but it waits for a long time on the files that in fact wanted user interaction (I mean files which without mentioning the NO UI it will ask the user for that file). This is my code: WINTRUST_FILE_INFO FileData; memset(&FileData, 0, sizeof(FileData)); FileData.cbStruct = sizeof(WINTRUST_FILE_INFO); wchar_t fileName[32769]; FileData.pcwszFilePath = fileName; FileData.hFile = NULL; FileData.pgKnownSubject = NULL; /* WVTPolicyGUID specifies the policy to apply on the file WINTRUST_ACTION_GENERIC_VERIFY_V2 policy checks: 1) The certificate used to sign the file chains up to a root certificate located in the trusted root certificate store. This implies that the identity of the publisher has been verified by a certification authority. 2) In cases where user interface is displayed (which this example does not do), WinVerifyTrust will check for whether the end entity certificate is stored in the trusted publisher store, implying that the user trusts content from this publisher. 3) The end entity certificate has sufficient permission to sign code, as indicated by the presence of a code signing EKU or no EKU. */ GUID WVTPolicyGUID = WINTRUST_ACTION_GENERIC_VERIFY_V2; WINTRUST_DATA WinTrustData; // Initialize the WinVerifyTrust input data structure. // Default all fields to 0. memset(&WinTrustData, 0, sizeof(WinTrustData)); WinTrustData.cbStruct = sizeof(WinTrustData); // Use default code signing EKU. WinTrustData.pPolicyCallbackData = NULL; // No data to pass to SIP. WinTrustData.pSIPClientData = NULL; // Disable WVT UI. WinTrustData.dwUIChoice = WTD_UI_NONE; // No revocation checking. WinTrustData.fdwRevocationChecks = WTD_REVOKE_NONE; // Verify an embedded signature on a file. WinTrustData.dwUnionChoice = WTD_CHOICE_FILE; // Default verification. WinTrustData.dwStateAction = 0; // Not applicable for default verification of embedded signature. WinTrustData.hWVTStateData = NULL; // Not used. WinTrustData.pwszURLReference = NULL; // Default. WinTrustData.dwProvFlags = WTD_REVOCATION_CHECK_END_CERT; // This is not applicable if there is no UI because it changes // the UI to accommodate running applications instead of // installing applications. WinTrustData.dwUIContext = 0; // Set pFile. WinTrustData.pFile = &FileData; // WinVerifyTrust verifies signatures as specified by the GUID // and Wintrust_Data. lStatus = WinVerifyTrust( (HWND)INVALID_HANDLE_VALUE, &WVTPolicyGUID, &WinTrustData); printf("%x\n", lStatus);

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• authentication problem on windows vista (cookie is getting written but httpcontext.current.user is n

  - by gaurav

  authentication problem on windows vista (iis7) (cookie is getting written but httpcontext.current.user is null)

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• start apache2 in chroot environment

  - by xero

  This is my first time I am trying to install Apache2 HTTP server in a chroot environment. That's why i decided to follow this procedure : http://www.symantec.com/connect/articles/securing-apache-2-step-step my web server start with successful : root@ubuntu:/usr/local/apache2/bin/apachectl start [Tue Oct 29 01:49:15.879868 2013] [core:warn] [pid 10835] AH00117: Ignoring deprecated use of DefaultType in line 60 of /usr/local/apache2/conf/httpd.conf. AH00548: NameVirtualHost has no effect and will be removed in the next release /usr/local/apache2/conf/httpd.conf:81 AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1. Set the 'ServerName' directive globally to suppress this message root@ubuntu:/chroot/httpd/etc# netstat -antu Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN But at the end of part "Chrooting the server" i have always the same problem. When i try to start apache2 in chroot i have always this error : root@ubuntu:/chroot/httpd/etc# chroot /chroot/httpd /usr/local/apache2/bin/apachectl chroot: failed to run command `/usr/local/apache2/bin/apachectl': No such file or directory however my apachectl file exist : root@ubuntu:/chroot/httpd/etc# ls -l /chroot/httpd/usr/local/apache2/bin/apachectl -rwxr-xr-x 1 root root 3437 Oct 29 02:28 /chroot/httpd/usr/local/apache2/bin/apachectl when I use strace to debug, there are errors with coreutils.mo and libc.mo : root@ubuntu:/chroot/httpd/etc# chroot /chroot/httpd /usr/local/apache2/bin/httpd group hosts nsswitch.conf passwd passwords resolv.conf root@ubuntu:/chroot/httpd/etc# strace chroot /chroot/httpd /usr/local/apache2/bin/apachectl execve("/usr/sbin/chroot", ["chroot", "/chroot/httpd", "/usr/local/apache2/bin/apachectl"], [/* 18 vars */]) = 0 brk(0) = 0x1e46000 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe89563b000 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory) open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=18263, ...}) = 0 mmap(NULL, 18263, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fe895636000 close(3) = 0 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3 read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\200\30\2\0\0\0\0\0"..., 832) = 832 fstat(3, {st_mode=S_IFREG|0755, st_size=1815224, ...}) = 0 mmap(NULL, 3929304, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fe89505b000 mprotect(0x7fe895210000, 2097152, PROT_NONE) = 0 mmap(0x7fe895410000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1b5000) = 0x7fe895410000 mmap(0x7fe895416000, 17624, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fe895416000 close(3) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe895635000 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe895634000 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe895633000 arch_prctl(ARCH_SET_FS, 0x7fe895634700) = 0 mprotect(0x7fe895410000, 16384, PROT_READ) = 0 mprotect(0x606000, 4096, PROT_READ) = 0 mprotect(0x7fe89563d000, 4096, PROT_READ) = 0 munmap(0x7fe895636000, 18263) = 0 brk(0) = 0x1e46000 brk(0x1e67000) = 0x1e67000 open("/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=2919792, ...}) = 0 mmap(NULL, 2919792, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fe894d92000 close(3) = 0 chroot("/chroot/httpd") = 0 chdir("/") = 0 execve("/usr/local/apache2/bin/apachectl", ["/usr/local/apache2/bin/apachectl"], [/* 18 vars */]) = -1 ENOENT (No such file or directory) open("/usr/share/locale/locale.alias", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory) open("/usr/share/locale/en_US.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale/en_US.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale/en_US/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale/en.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale/en.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale/en/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale-langpack/en_US.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale-langpack/en_US.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale-langpack/en_US/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale-langpack/en.UTF-8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale-langpack/en.utf8/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale-langpack/en/LC_MESSAGES/coreutils.mo", O_RDONLY) = -1 ENOENT (No such file or directory) write(2, "chroot: ", 8chroot: ) = 8 write(2, "failed to run command `/usr/loca"..., 56failed to run command `/usr/local/apache2/bin/apachectl') = 56 open("/usr/share/locale/en_US.UTF-8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale/en_US.utf8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale/en_US/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale/en.UTF-8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale/en.utf8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale/en/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale-langpack/en_US.UTF-8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale-langpack/en_US.utf8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale-langpack/en_US/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale-langpack/en.UTF-8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale-langpack/en.utf8/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory) open("/usr/share/locale-langpack/en/LC_MESSAGES/libc.mo", O_RDONLY) = -1 ENOENT (No such file or directory) write(2, ": No such file or directory", 27: No such file or directory) = 27 write(2, "\n", 1 ) = 1 close(1) = 0 close(2) = 0 exit_group(127) = ? using the tutorial I did not find and copie libraries following on my server. I suppose there is no link with coreutils.mo and libc.mo : /usr/libexec/ld-elf.so.1 /var/run/ld-elf.so.hints I don't understand what files i forgot to copy in my chroot environment to be able to start my apache2. Any ideas ?

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• Help With Database Layout

  - by three3

  Hello everyone, I am working on a site similar to Craigslist where users can make postings and sell items in different cities. One difference between my site and Craigslist will be you will be able to search by zip code instead of having all of the cities listed on the page. I already have the ZIP Code database that has all of the city, state, latitude, longitude, and zip code info for each city. Okay, so to dive into what I need done and what I need help with: 1.) Although I have the ZIP Code database, it is not setup perfectly for my use. (I downloaded it off of the internet for free from http://zips.sourceforge.net/) 2.) I need help setting up my database structure (Ex: How many different tables should I use and how should I link them) I will be using PHP and MySQL. These our my thoughts so far on how the database can be setup: (I am not sure if this will work though.) Scenario: Someone goes to the homepage and it will tell them, "Please enter your ZIP Code.". If they enter "17241" for example, this ZIP Code is for a city named Newville located in Pennsylvania. The query would look like this with the current database setup: SELECT city FROM zip_codes WHERE zip = 17241; The result of the query would be "Newville". The problem I see here now is when they want to post something in the Newville section of the site, I will have to have an entire table setup just for the Newville city postings. There are over 42,000 cities which means I would have to have over 42,000 tables (one for each city) so that would be insane to have to do it that way. One way I was thinking of doing it was to add a column to the ZIP Code database called "city_id" which would be a unique number assigned to each city. So for example, the city Newville would have a city_id of 83. So now if someone comes and post a listing in the city Newville I would only need one other table. That one other table would be setup like this: CREATE TABLE postings ( posting_id INT NOT NULL AUTO_INCREMENT, for_sale LONGTEXT NULL, for_sale_date DATETIME NULL, for_sale_city_id INT NULL, jobs LONGTEXT NULL, jobs_date DATETIME NULL, jobs_city_id INT NULL, PRIMARY KEY(posting_id) ); (The for_sale and job_ column names are categories of the types of postings users will be able to list under. There will be many more categories than just those two but this is just for example.) So now when when someone comes to the website and they are looking for something to buy and not sell, they can enter their ZIP Code, 17241, for example, and this is the query that will run: SELECT city, city_id FROM zip_codes WHERE zip = 17241; //Result: Newville 83 (Please note that I will be using PHP to store the ZIP Code the user enters in SESSIONS and Cookies to remember them throughout the site) Now it will tell them, "Please choose your category.". If they choose the category "Items For Sale" then this is the query to run and sort the results: SELECT posting_id, for_sale, for_sale_date FROM postings WHERE for_sale_city_id = $_SESSION['zip_code']; Will this work? So now my question to everyone is will this work? I am pretty sure it will but I do not want to set this thing up and realize I overlooked something and have to start from all over from scratch. Any opinions and ideas are welcomed and I will listen to anyone who has some thoughts. I really appreciate the help in advance :D

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• How to use Android's CacheManager?

  - by punnie

  I'm currently developing an Android application that fetches images using http requests. It would be quite swell if I could cache those images in order to improve to performance and bandwidth use. I came across the CacheManager class in the Android reference, but I don't really know how to use it, or what it really does. I already scoped through this example, but I need some help understanding it: /core/java/android/webkit/gears/ApacheHttpRequestAndroid.java Also, the reference states: "Network requests are provided to this component and if they can not be resolved by the cache, the HTTP headers are attached, as appropriate, to the request for revalidation of content." I'm not sure what this means or how it would work for me, since CacheManager's getCacheFile accepts only a String URL and a Map containing the headers. Not sure what the attachment mentioned means. An explanation or a simple code example would really do my day. Thanks! Update Here's what I have right now. I am clearly doing it wrong, just don't know where. public static Bitmap getRemoteImage(String imageUrl) { URL aURL = null; URLConnection conn = null; Bitmap bmp = null; CacheResult cache_result = CacheManager.getCacheFile(imageUrl, new HashMap()); if (cache_result == null) { try { aURL = new URL(imageUrl); conn = aURL.openConnection(); conn.connect(); InputStream is = conn.getInputStream(); cache_result = new CacheManager.CacheResult(); copyStream(is, cache_result.getOutputStream()); CacheManager.saveCacheFile(imageUrl, cache_result); } catch (Exception e) { return null; } } bmp = BitmapFactory.decodeStream(cache_result.getInputStream()); return bmp; }

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• Implementing a listview inside a sliding drawer with a listview already present

  - by Parker

  I have an app whose main class extends ListActivity: public class GUIPrototype extends ListActivity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); final Cursor c = managedQuery(People.CONTENT_URI, null, null, null, null); String[] from = new String[] {People.NAME}; int[] to = new int[] { R.id.row_entry }; SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,R.layout.drawer,c,from,to); setListAdapter(adapter); getListView().setTextFilterEnabled(true); } } I have a sliding drawer included in my XML, and I'm trying to get a separate listview to appear in the sliding drawer. I'm trying to populate the second listview using an inflater: View inflatedView = View.inflate(this, R.layout.main, null); ListView namesLV = (ListView) inflatedView.findViewById(R.id.content); String[] names2 = new String[] { "CS 345", "New Tag", "Untagged" }; ArrayAdapter<String> bb = new ArrayAdapter<String>(this, R.layout.main, R.id.row_entry, names2); namesLV.setAdapter(bb); This compiles, and runs, but the slidingdrawer is completely blank. My XML follows: <SlidingDrawer android:id="@+id/drawer" android:handle="@+id/handle" android:content="@+id/content" android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="vertical" android:layout_gravity="bottom"> <ImageView android:id="@id/handle" android:layout_width="48px" android:layout_height="48px" android:background="@drawable/icon"/> <ListView android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@id/content"/> </SlidingDrawer> I feel like I'm missing a vital step. I haven't found any resources on my problem by Googling, so any help would be greatly appreciated.

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• Getting problem while capturing image through web cam in Java -OpenCV code.

  - by Chetan

  Hi.. I am developing Face detector using OpenCV library in java... I have written sample code for this,but it is giving Error while capturing image. can any one help please. Here is the code import java.awt.; import java.awt.event.; import java.awt.image.MemoryImageSource; import hypermedia.video.OpenCV; @SuppressWarnings("serial") public class FaceDetection extends Frame implements Runnable { ///Main method. public static void main(String[] args) { //System.out.println( "\nOpenCV face detection sample\n" ); new FaceDetection(); } // program execution frame rate (millisecond) final int FRAME_RATE = 1000/30; OpenCV cv = null; // OpenCV Object Thread t = null; // the sample thread // the input video stream image Image frame = null; // list of all face detected area Rectangle[] squares = new Rectangle[0]; //** Setup Frame and Object(s). FaceDetection() { super( "Face Detection" ); // OpenCV setup cv = new OpenCV(); //cv.capture(1, 1, 100); cv.capture( 320, 240 ); cv.cascade( OpenCV.CASCADE_FRONTALFACE_ALT ); // frame setup this.setBounds( 100, 100, cv.width, cv.height ); this.setBackground( Color.BLACK ); this.setVisible( true ); this.addKeyListener( new KeyAdapter() { public void keyReleased( KeyEvent e ) { if ( e.getKeyCode()==KeyEvent.VK_ESCAPE ) { // ESC : release OpenCV resources cv.dispose(); System.exit(0); } } } ); // start running program t = new Thread( this ); t.start(); } // Draw video frame and each detected faces area. public void paint( Graphics g ) { // draw image g.drawImage( frame, 0, 0, null ); // draw squares g.setColor( Color.RED ); for( Rectangle rect : squares ) g.drawRect( rect.x, rect.y, rect.width, rect.height ); } @SuppressWarnings("static-access") public void run() { while( t!=null && cv!=null ) { try { t.sleep( FRAME_RATE ); // grab image from video stream cv.read(); // create a new image from cv pixels data MemoryImageSource mis = new MemoryImageSource( cv.width, cv.height, cv.pixels(), 0, cv.width ); frame = createImage( mis ); // detect faces squares = cv.detect( 1.2f, 2, OpenCV.HAAR_DO_CANNY_PRUNING, 20, 20 ); // of course, repaint repaint(); } catch( InterruptedException e ) {;} } } } Error while starting capture : device 0

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• C#/.NET Little Wonders: The Concurrent Collections (1 of 3)

  - by James Michael Hare

  Once again we consider some of the lesser known classes and keywords of C#.  In the next few weeks, we will discuss the concurrent collections and how they have changed the face of concurrent programming. This week’s post will begin with a general introduction and discuss the ConcurrentStack<T> and ConcurrentQueue<T>.  Then in the following post we’ll discuss the ConcurrentDictionary<T> and ConcurrentBag<T>.  Finally, we shall close on the third post with a discussion of the BlockingCollection<T>. For more of the "Little Wonders" posts, see the index here. A brief history of collections In the beginning was the .NET 1.0 Framework.  And out of this framework emerged the System.Collections namespace, and it was good.  It contained all the basic things a growing programming language needs like the ArrayList and Hashtable collections.  The main problem, of course, with these original collections is that they held items of type object which means you had to be disciplined enough to use them correctly or you could end up with runtime errors if you got an object of a type you weren't expecting. Then came .NET 2.0 and generics and our world changed forever!  With generics the C# language finally got an equivalent of the very powerful C++ templates.  As such, the System.Collections.Generic was born and we got type-safe versions of all are favorite collections.  The List<T> succeeded the ArrayList and the Dictionary<TKey,TValue> succeeded the Hashtable and so on.  The new versions of the library were not only safer because they checked types at compile-time, in many cases they were more performant as well.  So much so that it's Microsoft's recommendation that the System.Collections original collections only be used for backwards compatibility. So we as developers came to know and love the generic collections and took them into our hearts and embraced them.  The problem is, thread safety in both the original collections and the generic collections can be problematic, for very different reasons. Now, if you are only doing single-threaded development you may not care – after all, no locking is required.  Even if you do have multiple threads, if a collection is “load-once, read-many” you don’t need to do anything to protect that container from multi-threaded access, as illustrated below: 1: public static class OrderTypeTranslator 2: { 3: // because this dictionary is loaded once before it is ever accessed, we don't need to synchronize 4: // multi-threaded read access 5: private static readonly Dictionary<string, char> _translator = new Dictionary<string, char> 6: { 7: {"New", 'N'}, 8: {"Update", 'U'}, 9: {"Cancel", 'X'} 10: }; 11:  12: // the only public interface into the dictionary is for reading, so inherently thread-safe 13: public static char? Translate(string orderType) 14: { 15: char charValue; 16: if (_translator.TryGetValue(orderType, out charValue)) 17: { 18: return charValue; 19: } 20:  21: return null; 22: } 23: } Unfortunately, most of our computer science problems cannot get by with just single-threaded applications or with multi-threading in a load-once manner.  Looking at  today's trends, it's clear to see that computers are not so much getting faster because of faster processor speeds -- we've nearly reached the limits we can push through with today's technologies -- but more because we're adding more cores to the boxes.  With this new hardware paradigm, it is even more important to use multi-threaded applications to take full advantage of parallel processing to achieve higher application speeds. So let's look at how to use collections in a thread-safe manner. Using historical collections in a concurrent fashion The early .NET collections (System.Collections) had a Synchronized() static method that could be used to wrap the early collections to make them completely thread-safe.  This paradigm was dropped in the generic collections (System.Collections.Generic) because having a synchronized wrapper resulted in atomic locks for all operations, which could prove overkill in many multithreading situations.  Thus the paradigm shifted to having the user of the collection specify their own locking, usually with an external object: 1: public class OrderAggregator 2: { 3: private static readonly Dictionary<string, List<Order>> _orders = new Dictionary<string, List<Order>>(); 4: private static readonly _orderLock = new object(); 5:  6: public void Add(string accountNumber, Order newOrder) 7: { 8: List<Order> ordersForAccount; 9:  10: // a complex operation like this should all be protected 11: lock (_orderLock) 12: { 13: if (!_orders.TryGetValue(accountNumber, out ordersForAccount)) 14: { 15: _orders.Add(accountNumber, ordersForAccount = new List<Order>()); 16: } 17:  18: ordersForAccount.Add(newOrder); 19: } 20: } 21: } Notice how we’re performing several operations on the dictionary under one lock.  With the Synchronized() static methods of the early collections, you wouldn’t be able to specify this level of locking (a more macro-level).  So in the generic collections, it was decided that if a user needed synchronization, they could implement their own locking scheme instead so that they could provide synchronization as needed. The need for better concurrent access to collections Here’s the problem: it’s relatively easy to write a collection that locks itself down completely for access, but anything more complex than that can be difficult and error-prone to write, and much less to make it perform efficiently!  For example, what if you have a Dictionary that has frequent reads but in-frequent updates?  Do you want to lock down the entire Dictionary for every access?  This would be overkill and would prevent concurrent reads.  In such cases you could use something like a ReaderWriterLockSlim which allows for multiple readers in a lock, and then once a writer grabs the lock it blocks all further readers until the writer is done (in a nutshell).  This is all very complex stuff to consider. Fortunately, this is where the Concurrent Collections come in.  The Parallel Computing Platform team at Microsoft went through great pains to determine how to make a set of concurrent collections that would have the best performance characteristics for general case multi-threaded use. Now, as in all things involving threading, you should always make sure you evaluate all your container options based on the particular usage scenario and the degree of parallelism you wish to acheive. This article should not be taken to understand that these collections are always supperior to the generic collections. Each fills a particular need for a particular situation. Understanding what each container is optimized for is key to the success of your application whether it be single-threaded or multi-threaded. General points to consider with the concurrent collections The MSDN points out that the concurrent collections all support the ICollection interface. However, since the collections are already synchronized, the IsSynchronized property always returns false, and SyncRoot always returns null.  Thus you should not attempt to use these properties for synchronization purposes. Note that since the concurrent collections also may have different operations than the traditional data structures you may be used to.  Now you may ask why they did this, but it was done out of necessity to keep operations safe and atomic.  For example, in order to do a Pop() on a stack you have to know the stack is non-empty, but between the time you check the stack’s IsEmpty property and then do the Pop() another thread may have come in and made the stack empty!  This is why some of the traditional operations have been changed to make them safe for concurrent use. In addition, some properties and methods in the concurrent collections achieve concurrency by creating a snapshot of the collection, which means that some operations that were traditionally O(1) may now be O(n) in the concurrent models.  I’ll try to point these out as we talk about each collection so you can be aware of any potential performance impacts.  Finally, all the concurrent containers are safe for enumeration even while being modified, but some of the containers support this in different ways (snapshot vs. dirty iteration).  Once again I’ll highlight how thread-safe enumeration works for each collection. ConcurrentStack<T>: The thread-safe LIFO container The ConcurrentStack<T> is the thread-safe counterpart to the System.Collections.Generic.Stack<T>, which as you may remember is your standard last-in-first-out container.  If you think of algorithms that favor stack usage (for example, depth-first searches of graphs and trees) then you can see how using a thread-safe stack would be of benefit. The ConcurrentStack<T> achieves thread-safe access by using System.Threading.Interlocked operations.  This means that the multi-threaded access to the stack requires no traditional locking and is very, very fast! For the most part, the ConcurrentStack<T> behaves like it’s Stack<T> counterpart with a few differences: Pop() was removed in favor of TryPop() Returns true if an item existed and was popped and false if empty. PushRange() and TryPopRange() were added Allows you to push multiple items and pop multiple items atomically. Count takes a snapshot of the stack and then counts the items. This means it is a O(n) operation, if you just want to check for an empty stack, call IsEmpty instead which is O(1). ToArray() and GetEnumerator() both also take snapshots. This means that iteration over a stack will give you a static view at the time of the call and will not reflect updates. Pushing on a ConcurrentStack<T> works just like you’d expect except for the aforementioned PushRange() method that was added to allow you to push a range of items concurrently. 1: var stack = new ConcurrentStack<string>(); 2:  3: // adding to stack is much the same as before 4: stack.Push("First"); 5:  6: // but you can also push multiple items in one atomic operation (no interleaves) 7: stack.PushRange(new [] { "Second", "Third", "Fourth" }); For looking at the top item of the stack (without removing it) the Peek() method has been removed in favor of a TryPeek().  This is because in order to do a peek the stack must be non-empty, but between the time you check for empty and the time you execute the peek the stack contents may have changed.  Thus the TryPeek() was created to be an atomic check for empty, and then peek if not empty: 1: // to look at top item of stack without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (stack.TryPeek(out item)) 5: { 6: Console.WriteLine("Top item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Stack was empty."); 11: } Finally, to remove items from the stack, we have the TryPop() for single, and TryPopRange() for multiple items.  Just like the TryPeek(), these operations replace Pop() since we need to ensure atomically that the stack is non-empty before we pop from it: 1: // to remove items, use TryPop or TryPopRange to get multiple items atomically (no interleaves) 2: if (stack.TryPop(out item)) 3: { 4: Console.WriteLine("Popped " + item); 5: } 6:  7: // TryPopRange will only pop up to the number of spaces in the array, the actual number popped is returned. 8: var poppedItems = new string[2]; 9: int numPopped = stack.TryPopRange(poppedItems); 10:  11: foreach (var theItem in poppedItems.Take(numPopped)) 12: { 13: Console.WriteLine("Popped " + theItem); 14: } Finally, note that as stated before, GetEnumerator() and ToArray() gets a snapshot of the data at the time of the call.  That means if you are enumerating the stack you will get a snapshot of the stack at the time of the call.  This is illustrated below: 1: var stack = new ConcurrentStack<string>(); 2:  3: // adding to stack is much the same as before 4: stack.Push("First"); 5:  6: var results = stack.GetEnumerator(); 7:  8: // but you can also push multiple items in one atomic operation (no interleaves) 9: stack.PushRange(new [] { "Second", "Third", "Fourth" }); 10:  11: while(results.MoveNext()) 12: { 13: Console.WriteLine("Stack only has: " + results.Current); 14: } The only item that will be printed out in the above code is "First" because the snapshot was taken before the other items were added. This may sound like an issue, but it’s really for safety and is more correct.  You don’t want to enumerate a stack and have half a view of the stack before an update and half a view of the stack after an update, after all.  In addition, note that this is still thread-safe, whereas iterating through a non-concurrent collection while updating it in the old collections would cause an exception. ConcurrentQueue<T>: The thread-safe FIFO container The ConcurrentQueue<T> is the thread-safe counterpart of the System.Collections.Generic.Queue<T> class.  The concurrent queue uses an underlying list of small arrays and lock-free System.Threading.Interlocked operations on the head and tail arrays.  Once again, this allows us to do thread-safe operations without the need for heavy locks! The ConcurrentQueue<T> (like the ConcurrentStack<T>) has some departures from the non-concurrent counterpart.  Most notably: Dequeue() was removed in favor of TryDequeue(). Returns true if an item existed and was dequeued and false if empty. Count does not take a snapshot It subtracts the head and tail index to get the count.  This results overall in a O(1) complexity which is quite good.  It’s still recommended, however, that for empty checks you call IsEmpty instead of comparing Count to zero. ToArray() and GetEnumerator() both take snapshots. This means that iteration over a queue will give you a static view at the time of the call and will not reflect updates. The Enqueue() method on the ConcurrentQueue<T> works much the same as the generic Queue<T>: 1: var queue = new ConcurrentQueue<string>(); 2:  3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5: queue.Enqueue("Second"); 6: queue.Enqueue("Third"); For front item access, the TryPeek() method must be used to attempt to see the first item if the queue.  There is no Peek() method since, as you’ll remember, we can only peek on a non-empty queue, so we must have an atomic TryPeek() that checks for empty and then returns the first item if the queue is non-empty. 1: // to look at first item in queue without removing it, can use TryPeek. 2: // Note that there is no Peek(), this is because you need to check for empty first. TryPeek does. 3: string item; 4: if (queue.TryPeek(out item)) 5: { 6: Console.WriteLine("First item was " + item); 7: } 8: else 9: { 10: Console.WriteLine("Queue was empty."); 11: } Then, to remove items you use TryDequeue().  Once again this is for the same reason we have TryPeek() and not Peek(): 1: // to remove items, use TryDequeue. If queue is empty returns false. 2: if (queue.TryDequeue(out item)) 3: { 4: Console.WriteLine("Dequeued first item " + item); 5: } Just like the concurrent stack, the ConcurrentQueue<T> takes a snapshot when you call ToArray() or GetEnumerator() which means that subsequent updates to the queue will not be seen when you iterate over the results.  Thus once again the code below will only show the first item, since the other items were added after the snapshot. 1: var queue = new ConcurrentQueue<string>(); 2:  3: // adding to queue is much the same as before 4: queue.Enqueue("First"); 5:  6: var iterator = queue.GetEnumerator(); 7:  8: queue.Enqueue("Second"); 9: queue.Enqueue("Third"); 10:  11: // only shows First 12: while (iterator.MoveNext()) 13: { 14: Console.WriteLine("Dequeued item " + iterator.Current); 15: } Using collections concurrently You’ll notice in the examples above I stuck to using single-threaded examples so as to make them deterministic and the results obvious.  Of course, if we used these collections in a truly multi-threaded way the results would be less deterministic, but would still be thread-safe and with no locking on your part required! For example, say you have an order processor that takes an IEnumerable<Order> and handles each other in a multi-threaded fashion, then groups the responses together in a concurrent collection for aggregation.  This can be done easily with the TPL’s Parallel.ForEach(): 1: public static IEnumerable<OrderResult> ProcessOrders(IEnumerable<Order> orderList) 2: { 3: var proxy = new OrderProxy(); 4: var results = new ConcurrentQueue<OrderResult>(); 5:  6: // notice that we can process all these in parallel and put the results 7: // into our concurrent collection without needing any external locking! 8: Parallel.ForEach(orderList, 9: order => 10: { 11: var result = proxy.PlaceOrder(order); 12:  13: results.Enqueue(result); 14: }); 15:  16: return results; 17: } Summary Obviously, if you do not need multi-threaded safety, you don’t need to use these collections, but when you do need multi-threaded collections these are just the ticket! The plethora of features (I always think of the movie The Three Amigos when I say plethora) built into these containers and the amazing way they acheive thread-safe access in an efficient manner is wonderful to behold. Stay tuned next week where we’ll continue our discussion with the ConcurrentBag<T> and the ConcurrentDictionary<TKey,TValue>. For some excellent information on the performance of the concurrent collections and how they perform compared to a traditional brute-force locking strategy, see this wonderful whitepaper by the Microsoft Parallel Computing Platform team here.   Tweet Technorati Tags: C#,.NET,Concurrent Collections,Collections,Multi-Threading,Little Wonders,BlackRabbitCoder,James Michael Hare

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• How to send messages between c++ .dll and C# app using named pipe?

  - by Gal

  I'm making an injected .dll written in C++, and I want to communicate with a C# app using named pipes. Now, I am using the built in System.IO.Pipe .net classes in the C# app, and I'm using the regular functions in C++. I don't have much experience in C++ (Read: This is my first C++ code..), tho I'm experienced in C#. It seems that the connection with the server and the client is working, the only problem is the messaged aren't being send. I tried making the .dll the server, the C# app the server, making the pipe direction InOut (duplex) but none seems to work. When I tried to make the .dll the server, which sends messages to the C# app, the code I used was like this: DWORD ServerCreate() // function to create the server and wait till it successfully creates it to return. { hPipe = CreateNamedPipe(pipename,//The unique pipe name. This string must have the following form: \\.\pipe\pipename PIPE_ACCESS_DUPLEX, PIPE_TYPE_MESSAGE | PIPE_READMODE_MESSAGE | PIPE_NOWAIT, //write and read and return right away PIPE_UNLIMITED_INSTANCES,//The maximum number of instances that can be created for this pipe 4096 , // output time-out 4096 , // input time-out 0,//client time-out NULL); if(hPipe== INVALID_HANDLE_VALUE) { return 1;//failed } else return 0;//success } void SendMsg(string msg) { DWORD cbWritten; WriteFile(hPipe,msg.c_str(), msg.length()+1, &cbWritten,NULL); } void ProccesingPipeInstance() { while(ServerCreate() == 1)//if failed { Sleep(1000); } //if created success, wait to connect ConnectNamedPipe(hPipe, NULL); for(;;) { SendMsg("HI!"); if( ConnectNamedPipe(hPipe, NULL)==0) if(GetLastError()==ERROR_NO_DATA) { DebugPrintA("previous closed,ERROR_NO_DATA"); DisconnectNamedPipe(hPipe); ConnectNamedPipe(hPipe, NULL); } Sleep(1000); } And the C# cliend like this: static void Main(string[] args) { Console.WriteLine("Hello!"); using (var pipe = new NamedPipeClientStream(".", "HyprPipe", PipeDirection.In)) { Console.WriteLine("Created Client!"); Console.Write("Connecting to pipe server in the .dll ..."); pipe.Connect(); Console.WriteLine("DONE!"); using (var pr = new StreamReader(pipe)) { string t; while ((t = pr.ReadLine()) != null) { Console.WriteLine("Message: {0}",t); } } } } I see that the C# client connected to the .dll, but it won't receive any message.. I tried doing it the other way around, as I said before, and trying to make the C# send messages to the .dll, which would show them in a message box. The .dll was injected and connected to the C# server, but when It received a message it just crashed the application it was injected to. Please help me, or guide me on how to use named pipes between C++ and C# app

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• How I can add JScroll bar to NavigableImagePanel which is an Image panel with an small navigation vi

  - by Sarah Kho

  Hi, I have the following NavigableImagePanel, it is under BSD license and I found it in the web. What I want to do with this panel is as follow: I want to add a JScrollPane to it in order to show images in their full size and let the users to re-center the image using the small navigation panel. Right now, the panel resize the images to fit them in the current panel size. I want it to load the image in its real size and let users to navigate to different parts of the image using the navigation panel. Source code for the panel: import java.awt.AWTEvent; import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.GraphicsEnvironment; import java.awt.Image; import java.awt.Point; import java.awt.Rectangle; import java.awt.RenderingHints; import java.awt.Toolkit; import java.awt.event.ComponentAdapter; import java.awt.event.ComponentEvent; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.MouseMotionListener; import java.awt.event.MouseWheelEvent; import java.awt.event.MouseWheelListener; import java.awt.image.BufferedImage; import java.io.File; import java.io.IOException; import java.util.Arrays; import javax.imageio.ImageIO; import javax.swing.JFrame; import javax.swing.JOptionPane; import javax.swing.JPanel; import javax.swing.SwingUtilities; /** * @author pxt * */ public class NavigableImagePanel extends JPanel { /** * <p>Identifies a change to the zoom level.</p> */ public static final String ZOOM_LEVEL_CHANGED_PROPERTY = "zoomLevel"; /** * <p>Identifies a change to the zoom increment.</p> */ public static final String ZOOM_INCREMENT_CHANGED_PROPERTY = "zoomIncrement"; /** * <p>Identifies that the image in the panel has changed.</p> */ public static final String IMAGE_CHANGED_PROPERTY = "image"; private static final double SCREEN_NAV_IMAGE_FACTOR = 0.15; // 15% of panel's width private static final double NAV_IMAGE_FACTOR = 0.3; // 30% of panel's width private static final double HIGH_QUALITY_RENDERING_SCALE_THRESHOLD = 1.0; private static final Object INTERPOLATION_TYPE = RenderingHints.VALUE_INTERPOLATION_BILINEAR; private double zoomIncrement = 0.2; private double zoomFactor = 1.0 + zoomIncrement; private double navZoomFactor = 1.0 + zoomIncrement; private BufferedImage image; private BufferedImage navigationImage; private int navImageWidth; private int navImageHeight; private double initialScale = 0.0; private double scale = 0.0; private double navScale = 0.0; private int originX = 0; private int originY = 0; private Point mousePosition; private Dimension previousPanelSize; private boolean navigationImageEnabled = true; private boolean highQualityRenderingEnabled = true; private WheelZoomDevice wheelZoomDevice = null; private ButtonZoomDevice buttonZoomDevice = null; /** * <p>Defines zoom devices.</p> */ public static class ZoomDevice { /** * <p>Identifies that the panel does not implement zooming, * but the component using the panel does (programmatic zooming method).</p> */ public static final ZoomDevice NONE = new ZoomDevice("none"); /** * <p>Identifies the left and right mouse buttons as the zooming device.</p> */ public static final ZoomDevice MOUSE_BUTTON = new ZoomDevice("mouseButton"); /** * <p>Identifies the mouse scroll wheel as the zooming device.</p> */ public static final ZoomDevice MOUSE_WHEEL = new ZoomDevice("mouseWheel"); private String zoomDevice; private ZoomDevice(String zoomDevice) { this.zoomDevice = zoomDevice; } public String toString() { return zoomDevice; } } //This class is required for high precision image coordinates translation. private class Coords { public double x; public double y; public Coords(double x, double y) { this.x = x; this.y = y; } public int getIntX() { return (int)Math.round(x); } public int getIntY() { return (int)Math.round(y); } public String toString() { return "[Coords: x=" + x + ",y=" + y + "]"; } } private class WheelZoomDevice implements MouseWheelListener { public void mouseWheelMoved(MouseWheelEvent e) { Point p = e.getPoint(); boolean zoomIn = (e.getWheelRotation() < 0); if (isInNavigationImage(p)) { if (zoomIn) { navZoomFactor = 1.0 + zoomIncrement; } else { navZoomFactor = 1.0 - zoomIncrement; } zoomNavigationImage(); } else if (isInImage(p)) { if (zoomIn) { zoomFactor = 1.0 + zoomIncrement; } else { zoomFactor = 1.0 - zoomIncrement; } zoomImage(); } } } private class ButtonZoomDevice extends MouseAdapter { public void mouseClicked(MouseEvent e) { Point p = e.getPoint(); if (SwingUtilities.isRightMouseButton(e)) { if (isInNavigationImage(p)) { navZoomFactor = 1.0 - zoomIncrement; zoomNavigationImage(); } else if (isInImage(p)) { zoomFactor = 1.0 - zoomIncrement; zoomImage(); } } else { if (isInNavigationImage(p)) { navZoomFactor = 1.0 + zoomIncrement; zoomNavigationImage(); } else if (isInImage(p)) { zoomFactor = 1.0 + zoomIncrement; zoomImage(); } } } } /** * <p>Creates a new navigable image panel with no default image and * the mouse scroll wheel as the zooming device.</p> */ public NavigableImagePanel() { setOpaque(false); addComponentListener(new ComponentAdapter() { public void componentResized(ComponentEvent e) { if (scale > 0.0) { if (isFullImageInPanel()) { centerImage(); } else if (isImageEdgeInPanel()) { scaleOrigin(); } if (isNavigationImageEnabled()) { createNavigationImage(); } repaint(); } previousPanelSize = getSize(); } }); addMouseListener(new MouseAdapter() { public void mousePressed(MouseEvent e) { if (SwingUtilities.isLeftMouseButton(e)) { if (isInNavigationImage(e.getPoint())) { Point p = e.getPoint(); displayImageAt(p); } } } public void mouseClicked(MouseEvent e){ if (e.getClickCount() == 2) { resetImage(); } } }); addMouseMotionListener(new MouseMotionListener() { public void mouseDragged(MouseEvent e) { if (SwingUtilities.isLeftMouseButton(e) && !isInNavigationImage(e.getPoint())) { Point p = e.getPoint(); moveImage(p); } } public void mouseMoved(MouseEvent e) { //we need the mouse position so that after zooming //that position of the image is maintained mousePosition = e.getPoint(); } }); setZoomDevice(ZoomDevice.MOUSE_WHEEL); } /** * <p>Creates a new navigable image panel with the specified image * and the mouse scroll wheel as the zooming device.</p> */ public NavigableImagePanel(BufferedImage image) throws IOException { this(); setImage(image); } private void addWheelZoomDevice() { if (wheelZoomDevice == null) { wheelZoomDevice = new WheelZoomDevice(); addMouseWheelListener(wheelZoomDevice); } } private void addButtonZoomDevice() { if (buttonZoomDevice == null) { buttonZoomDevice = new ButtonZoomDevice(); addMouseListener(buttonZoomDevice); } } private void removeWheelZoomDevice() { if (wheelZoomDevice != null) { removeMouseWheelListener(wheelZoomDevice); wheelZoomDevice = null; } } private void removeButtonZoomDevice() { if (buttonZoomDevice != null) { removeMouseListener(buttonZoomDevice); buttonZoomDevice = null; } } /** * <p>Sets a new zoom device.</p> * * @param newZoomDevice specifies the type of a new zoom device. */ public void setZoomDevice(ZoomDevice newZoomDevice) { if (newZoomDevice == ZoomDevice.NONE) { removeWheelZoomDevice(); removeButtonZoomDevice(); } else if (newZoomDevice == ZoomDevice.MOUSE_BUTTON) { removeWheelZoomDevice(); addButtonZoomDevice(); } else if (newZoomDevice == ZoomDevice.MOUSE_WHEEL) { removeButtonZoomDevice(); addWheelZoomDevice(); } } /** * <p>Gets the current zoom device.</p> */ public ZoomDevice getZoomDevice() { if (buttonZoomDevice != null) { return ZoomDevice.MOUSE_BUTTON; } else if (wheelZoomDevice != null) { return ZoomDevice.MOUSE_WHEEL; } else { return ZoomDevice.NONE; } } //Called from paintComponent() when a new image is set. private void initializeParams() { double xScale = (double)getWidth() / image.getWidth(); double yScale = (double)getHeight() / image.getHeight(); initialScale = Math.min(xScale, yScale); scale = initialScale; //An image is initially centered centerImage(); if (isNavigationImageEnabled()) { createNavigationImage(); } } //Centers the current image in the panel. private void centerImage() { originX = (int)(getWidth() - getScreenImageWidth()) / 2; originY = (int)(getHeight() - getScreenImageHeight()) / 2; } //Creates and renders the navigation image in the upper let corner of the panel. private void createNavigationImage() { //We keep the original navigation image larger than initially //displayed to allow for zooming into it without pixellation effect. navImageWidth = (int)(getWidth() * NAV_IMAGE_FACTOR); navImageHeight = navImageWidth * image.getHeight() / image.getWidth(); int scrNavImageWidth = (int)(getWidth() * SCREEN_NAV_IMAGE_FACTOR); int scrNavImageHeight = scrNavImageWidth * image.getHeight() / image.getWidth(); navScale = (double)scrNavImageWidth / navImageWidth; navigationImage = new BufferedImage(navImageWidth, navImageHeight, image.getType()); Graphics g = navigationImage.getGraphics(); g.drawImage(image, 0, 0, navImageWidth, navImageHeight, null); } /** * <p>Sets an image for display in the panel.</p> * * @param image an image to be set in the panel */ public void setImage(BufferedImage image) { BufferedImage oldImage = this.image; this.image = image; //Reset scale so that initializeParameters() is called in paintComponent() //for the new image. scale = 0.0; firePropertyChange(IMAGE_CHANGED_PROPERTY, (Image)oldImage, (Image)image); repaint(); } /** * <p>resets an image to the centre of the panel</p> * */ public void resetImage() { BufferedImage oldImage = this.image; this.image = image; //Reset scale so that initializeParameters() is called in paintComponent() //for the new image. scale = 0.0; firePropertyChange(IMAGE_CHANGED_PROPERTY, (Image)oldImage, (Image)image); repaint(); } /** * <p>Tests whether an image uses the standard RGB color space.</p> */ public static boolean isStandardRGBImage(BufferedImage bImage) { return bImage.getColorModel().getColorSpace().isCS_sRGB(); } //Converts this panel's coordinates into the original image coordinates private Coords panelToImageCoords(Point p) { return new Coords((p.x - originX) / scale, (p.y - originY) / scale); } //Converts the original image coordinates into this panel's coordinates private Coords imageToPanelCoords(Coords p) { return new Coords((p.x * scale) + originX, (p.y * scale) + originY); } //Converts the navigation image coordinates into the zoomed image coordinates private Point navToZoomedImageCoords(Point p) { int x = p.x * getScreenImageWidth() / getScreenNavImageWidth(); int y = p.y * getScreenImageHeight() / getScreenNavImageHeight(); return new Point(x, y); } //The user clicked within the navigation image and this part of the image //is displayed in the panel. //The clicked point of the image is centered in the panel. private void displayImageAt(Point p) { Point scrImagePoint = navToZoomedImageCoords(p); originX = -(scrImagePoint.x - getWidth() / 2); originY = -(scrImagePoint.y - getHeight() / 2); repaint(); } //Tests whether a given point in the panel falls within the image boundaries. private boolean isInImage(Point p) { Coords coords = panelToImageCoords(p); int x = coords.getIntX(); int y = coords.getIntY(); return (x >= 0 && x < image.getWidth() && y >= 0 && y < image.getHeight()); } //Tests whether a given point in the panel falls within the navigation image //boundaries. private boolean isInNavigationImage(Point p) { return (isNavigationImageEnabled() && p.x < getScreenNavImageWidth() && p.y < getScreenNavImageHeight()); } //Used when the image is resized. private boolean isImageEdgeInPanel() { if (previousPanelSize == null) { return false; } return (originX > 0 && originX < previousPanelSize.width || originY > 0 && originY < previousPanelSize.height); } //Tests whether the image is displayed in its entirety in the panel. private boolean isFullImageInPanel() { return (originX >= 0 && (originX + getScreenImageWidth()) < getWidth() && originY >= 0 && (originY + getScreenImageHeight()) < getHeight()); } /** * <p>Indicates whether the high quality rendering feature is enabled.</p> * * @return true if high quality rendering is enabled, false otherwise. */ public boolean isHighQualityRenderingEnabled() { return highQualityRenderingEnabled; } /** * <p>Enables/disables high quality rendering.</p> * * @param enabled enables/disables high quality rendering */ public void setHighQualityRenderingEnabled(boolean enabled) { highQualityRenderingEnabled = enabled; } //High quality rendering kicks in when when a scaled image is larger //than the original image. In other words, //when image decimation stops and interpolation starts. private boolean isHighQualityRendering() { return (highQualityRenderingEnabled && scale > HIGH_QUALITY_RENDERING_SCALE_THRESHOLD); } /** * <p>Indicates whether navigation image is enabled.<p> * * @return true when navigation image is enabled, false otherwise. */ public boolean isNavigationImageEnabled() { return navigationImageEnabled; } /** * <p>Enables/disables navigation with the navigation image.</p> * <p>Navigation image should be disabled when custom, programmatic navigation * is implemented.</p> * * @param enabled true when navigation image is enabled, false otherwise. */ public void setNavigationImageEnabled(boolean enabled) { navigationImageEnabled = enabled; repaint(); } //Used when the panel is resized private void scaleOrigin() { originX = originX * getWidth() / previousPanelSize.width; originY = originY * getHeight() / previousPanelSize.height; repaint(); } //Converts the specified zoom level to scale. private double zoomToScale(double zoom) { return initialScale * zoom; } /** * <p>Gets the current zoom level.</p> * * @return the current zoom level */ public double getZoom() { return scale / initialScale; } /** * <p>Sets the zoom level used to display the image.</p> * <p>This method is used in programmatic zooming. The zooming center is * the point of the image closest to the center of the panel. * After a new zoom level is set the image is repainted.</p> * * @param newZoom the zoom level used to display this panel's image. */ public void setZoom(double newZoom) { Point zoomingCenter = new Point(getWidth() / 2, getHeight() / 2); setZoom(newZoom, zoomingCenter); } /** * <p>Sets the zoom level used to display the image, and the zooming center, * around which zooming is done.</p> * <p>This method is used in programmatic zooming. * After a new zoom level is set the image is repainted.</p> * * @param newZoom the zoom level used to display this panel's image. */ public void setZoom(double newZoom, Point zoomingCenter) { Coords imageP = panelToImageCoords(zoomingCenter); if (imageP.x < 0.0) { imageP.x = 0.0; } if (imageP.y < 0.0) { imageP.y = 0.0; } if (imageP.x >= image.getWidth()) { imageP.x = image.getWidth() - 1.0; } if (imageP.y >= image.getHeight()) { imageP.y = image.getHeight() - 1.0; } Coords correctedP = imageToPanelCoords(imageP); double oldZoom = getZoom(); scale = zoomToScale(newZoom); Coords panelP = imageToPanelCoords(imageP); originX += (correctedP.getIntX() - (int)panelP.x); originY += (correctedP.getIntY() - (int)panelP.y); firePropertyChange(ZOOM_LEVEL_CHANGED_PROPERTY, new Double(oldZoom), new Double(getZoom())); repaint(); } /** * <p>Gets the current zoom increment.</p> * * @return the current zoom increment */ public double getZoomIncrement() { return zoomIncrement; } /** * <p>Sets a new zoom increment value.</p> * * @param newZoomIncrement new zoom increment value */ public void setZoomIncrement(double newZoomIncrement) { double oldZoomIncrement = zoomIncrement; zoomIncrement = newZoomIncrement; firePropertyChange(ZOOM_INCREMENT_CHANGED_PROPERTY, new Double(oldZoomIncrement), new Double(zoomIncrement)); } //Zooms an image in the panel by repainting it at the new zoom level. //The current mouse position is the zooming center. private void zoomImage() { Coords imageP = panelToImageCoords(mousePosition); double oldZoom = getZoom(); scale *= zoomFactor; Coords panelP = imageToPanelCoords(imageP); originX += (mousePosition.x - (int)panelP.x); originY += (mousePosition.y - (int)panelP.y); firePropertyChange(ZOOM_LEVEL_CHANGED_PROPERTY, new Double(oldZoom), new Double(getZoom())); repaint(); } //Zooms the navigation image private void zoomNavigationImage() { navScale *= navZoomFactor; repaint(); } /** * <p>Gets the image origin.</p> * <p>Image origin is defined as the upper, left corner of the image in * the panel's coordinate system.</p> * @return the point of the upper, left corner of the image in the panel's coordinates * system. */ public Point getImageOrigin() { return new Point(originX, originY); } /** * <p>Sets the image origin.</p> * <p>Image origin is defined as the upper, left corner of the image in * the panel's coordinate system. After a new origin is set, the image is repainted. * This method is used for programmatic image navigation.</p>

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• Flex secret for session using Facebook API

  - by Mike

  In this video, it mentioned not to embed the Facebook secret key inside the application, http://www.adobe.com/devnet/facebook/articles/video_facebook_quick_start.html, so I passed null to this function facebookSession = new FacebookSessionUtil(MYAPI, null, stage.loaderInfo); but it didn't work. How can I hide my secret key? In the doc it mentioned: http://facebook-actionscript-api.googlecode.com/svn/release/current/docs/com/facebook/utils/FacebookSessionUtil.html secret:String — Your application's secret key. If this parameter is passed a value of null, the constructor looks for a special session secret stored in the fb_sig_ss property of the loaderInfo object. For web sessions, even if you pass a non-null value for this parameter, the constructor will always look for a session secret and use that instead of the value that you pass for this parameter.

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• Android mapView ItemizedOverlay setFocus does not work properly

  - by Gaks

  Calling setFocus(null) on the ItemizedOverlay does not 'unfocus' current marker. According to the documentation: ... If the Item is not found, this is a no-op. You can also pass null to remove focus. Here's my code: MapItemizedOverlay public class MapItemizedOverlay extends ItemizedOverlay<OverlayItem> { private ArrayList<OverlayItem> items = new ArrayList<OverlayItem>(); public MapItemizedOverlay(Drawable defaultMarker) { super(defaultMarker); } public void addOverlay(OverlayItem overlay) { items.add(overlay); populate(); } @Override protected OverlayItem createItem(int i) { return items.get(i); } @Override public int size() { return items.size(); } } Creating map overlay and one marker: StateListDrawable youIcon = (StateListDrawable)getResources().getDrawable(R.drawable.marker_icon); int width = youIcon.getIntrinsicWidth(); int height = youIcon.getIntrinsicHeight(); youIcon.setBounds(-13, 0-height, -13+width, 0); GeoPoint location = new GeoPoint(40800816,-74122009); MapItemizedOverlay overlay = new MapItemizedOverlay(youIcon); OverlayItem item = new OverlayItem(location, "title", "snippet"); overlay.addOverlay(item); mapView.getOverlays().add(overlay); The R.drawable.marker_icon is defined as follows: <?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:state_focused="true" android:drawable="@drawable/marker_selected" /> <item android:state_selected="true" android:drawable="@drawable/marker_selected" /> <item android:drawable="@drawable/marker_normal" /> </selector> Now, to test the setFocus() behavior I put the button on the activity window, with the following onClick listener: Button focusBtn = (Button)findViewById(R.id.focusbtn); focusBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { for(Overlay ov : mapView.getOverlays()) { if(ov.getClass().getSimpleName().equals("MapItemizedOverlay") == true) { MapItemizedOverlay miv = (MapItemizedOverlay)ov; if(miv.getFocus() == null) miv.setFocus(miv.getItem(0)); else miv.setFocus(null); break; } } mapView.invalidate(); } }); The expected behavior is: clicking on the button toggles marker selection. It works only once - clicking it for the first time selects the marker, clicking it again does not de-select the marker. The most weird thing about it is that after calling setFocus(null), getFocus() also returns null - like the overlay has no focused item (I debugged it). But even after calling mapView.invalidate() the marker is still drawn in 'selected'(focused) state.

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• Problem hosting WebBrowser control in an ATL app.

  - by Andrew Bucknell

  I have a legacy atl app that hosts a webbrowser control in an ATL window. I create an instance of the client to host the browser using the following sequence CComPtr<IOleObject> spOleObject; HRESULT hr = CoCreateInstance(CLSID_WebBrowser, NULL, CLSCTX_INPROC, ID_IOleObject,(void**)&spOleObject); spOleObject->SetClientSite(this); GetClientRect(&rcClient); hr = spOleObject->DoVerb(OLEIVERB_INPLACEACTIVATE, &msg, this, 0, m_hWnd, &rcClient); hr = AtlAdvise(m_spWebBrowser, GetUnknown(), DIID_DWebBrowserEvents2, &m_dwCookie); CComVariant navvar(navurl); m_spWebBrowser->Navigate2(&navvar, NULL, NULL, NULL, NULL); This sequence works fine to create the initial browse window. The call to navigate2 works and if I look at the window via spy++ I have Shell Embedding - Shell DocObject View - Internet Explorer_Server. When a popup occurs (detected through NewWindow3) I launch a new window and execute the same code sequence for the new window. In the popup window the navigate2 doesnt work, and when I look at this new window in spy++ I just have Shell Embedding. I get the same problem even if I instantiate the popup window on startup, so its not related to NewWindow3 at all - it seems the second instance of the web control isnt instantiating even though all the calls return S_OK. This sequence worked fine under IE7 but now I am using IE8 and the popup window isnt working. There is clearly something I am missing but I cant guess what it may be. Any suggestions would be incredibly helpful.

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• Calling notifyDataSetChanged doesn't fire onContentChanged event of SimpleCursorAdapter

  - by Pentium10

  I have this scenario onResume of an activity: @Override protected void onResume() { if (adapter1!=null) adapter1.notifyDataSetChanged(); if (adapter2!=null) adapter2.notifyDataSetChanged(); if (adapter3!=null) adapter3.notifyDataSetChanged(); super.onResume(); } Adapter has been defined as: public class ListCursorAdapter extends SimpleCursorAdapter { Cursor c; /* (non-Javadoc) * @see android.widget.CursorAdapter#onContentChanged() */ @Override protected void onContentChanged() { // this is not called if (c!=null) c.requery(); super.onContentChanged(); } } And the onContentChanged event is not fired, although the onResume and the call to the adapter is issued. What is wrong?

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• C# serial port driver wrapper class code and concept quality

  - by Ruben Trancoso

  Hi folks, Would like to know from all you guys what you think about my Serial Wrapper class. Had be a while I've beem working with serial port but never shared the code what somekind make closed to my very own vision. Would like to know if it's a good/bad approach, if the interface is enough and what more you see on it. I know that Stackoverflow is for question but at the same time there's a lot of very good skilled people here and share code and opinion can also bennefit everybody, it's why I decided to post it anyway. thanks! using System.Text; using System.IO; using System.IO.Ports; using System; namespace Driver { class SerialSingleton { // The singleton instance reference private static SerialSingleton instance = null; // System's serial port interface private SerialPort serial; // Current com port identifier private string comPort = null; // Configuration parameters private int confBaudRate; private int confDataBits; private StopBits confStopBits; private Parity confParityControl; ASCIIEncoding encoding = new ASCIIEncoding(); // ================================================================================== // Constructors public static SerialSingleton getInstance() { if (instance == null) { instance = new SerialSingleton(); } return instance; } private SerialSingleton() { serial = new SerialPort(); } // =================================================================================== // Setup Methods public string ComPort { get { return comPort; } set { if (value == null) { throw new SerialException("Serial port name canot be null."); } if (nameIsComm(value)) { close(); comPort = value; } else { throw new SerialException("Serial Port '" + value + "' is not a valid com port."); } } } public void setSerial(string baudRate, int dataBits, StopBits stopBits, Parity parityControl) { if (baudRate == null) { throw new SerialException("Baud rate cannot be null"); } string[] baudRateRef = { "300", "600", "1200", "1800", "2400", "3600", "4800", "7200", "9600", "14400", "19200", "28800", "38400", "57600", "115200" }; int confBaudRate; if (findString(baudRateRef, baudRate) != -1) { confBaudRate = System.Convert.ToInt32(baudRate); } else { throw new SerialException("Baurate parameter invalid."); } int confDataBits; switch (dataBits) { case 5: confDataBits = 5; break; case 6: confDataBits = 6; break; case 7: confDataBits = 7; break; case 8: confDataBits = 8; break; default: throw new SerialException("Databits parameter invalid"); } if (stopBits == StopBits.None) { throw new SerialException("StopBits parameter cannot be NONE"); } this.confBaudRate = confBaudRate; this.confDataBits = confDataBits; this.confStopBits = stopBits; this.confParityControl = parityControl; } // ================================================================================== public string[] PortList { get { return SerialPort.GetPortNames(); } } public int PortCount { get { return SerialPort.GetPortNames().Length; } } // ================================================================================== // Open/Close Methods public void open() { open(comPort); } private void open(string comPort) { if (isOpen()) { throw new SerialException("Serial Port is Already open"); } else { if (comPort == null) { throw new SerialException("Serial Port not defined. Cannot open"); } bool found = false; if (nameIsComm(comPort)) { string portId; string[] portList = SerialPort.GetPortNames(); for (int i = 0; i < portList.Length; i++) { portId = (portList[i]); if (portId.Equals(comPort)) { found = true; break; } } } else { throw new SerialException("The com port identifier '" + comPort + "' is not a valid serial port identifier"); } if (!found) { throw new SerialException("Serial port '" + comPort + "' not found"); } serial.PortName = comPort; try { serial.Open(); } catch (UnauthorizedAccessException uaex) { throw new SerialException("Cannot open a serial port in use by another application", uaex); } try { serial.BaudRate = confBaudRate; serial.DataBits = confDataBits; serial.Parity = confParityControl; serial.StopBits = confStopBits; } catch (Exception e) { throw new SerialException("Serial port parameter invalid for '" + comPort + "'.\n" + e.Message, e); } } } public void close() { if (serial.IsOpen) { serial.Close(); } } // =================================================================================== // Auxiliary private Methods private int findString(string[] set, string search) { if (set != null) { for (int i = 0; i < set.Length; i++) { if (set[i].Equals(search)) { return i; } } } return -1; } private bool nameIsComm(string name) { int comNumber; int.TryParse(name.Substring(3), out comNumber); if (name.Substring(0, 3).Equals("COM")) { if (comNumber > -1 && comNumber < 256) { return true; } } return false; } // ================================================================================= // Device state Methods public bool isOpen() { return serial.IsOpen; } public bool hasData() { int amount = serial.BytesToRead; if (amount > 0) { return true; } else { return false; } } // ================================================================================== // Input Methods public char getChar() { int data = serial.ReadByte(); return (char)data; } public int getBytes(ref byte[] b) { int size = b.Length; char c; int counter = 0; for (counter = 0; counter < size; counter++) { if (tryGetChar(out c)) { b[counter] = (byte)c; } else { break; } } return counter; } public string getStringUntil(char x) { char c; string response = ""; while (tryGetChar(out c)) { response = response + c; if (c == x) { break; } } return response; } public bool tryGetChar(out char c) { c = (char)0x00; byte[] b = new byte[1]; long to = 10; long ft = System.Environment.TickCount + to; while (System.Environment.TickCount < ft) { if (hasData()) { int data = serial.ReadByte(); c = (char)data; return true; } } return false; } // ================================================================================ // Output Methods public void sendString(string data) { byte[] bytes = encoding.GetBytes(data); serial.Write(bytes, 0, bytes.Length); } public void sendChar(char c) { char[] data = new char[1]; data[0] = c; serial.Write(data, 0, 1); } public void sendBytes(byte[] data) { serial.Write(data, 0, data.Length); } public void clearBuffer() { if (serial.IsOpen) { serial.DiscardInBuffer(); serial.DiscardOutBuffer(); } } } }

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• Why 32-bit color EGL configurations fail with EGL_BAD_MATCH on Moto Droid?

  - by Gilead

  I'm trying to figure out why certain EGL configurations cause eglMakeCurrent() call to return EGL_BAD_MATCH on Motorola Droid running Android 2.1u1. This is a full list of hardware-accelerated EGL configurations (those with EGL_CONFIG_CAVEAT == EGL_NONE) as there's a few others with EGL_CONFIG_CAVEAT == EGL_SLOW_CONFIG but those are backed by PixelFlinger 1.2 meaning they're using software renderer. ID: 0 RGB: 8, 8, 8 Alpha: 8 Depth: 24 Stencil: 8 // BAD MATCH ID: 1 RGB: 8, 8, 8 Alpha: 8 Depth: 0 Stencil: 0 // BAD MATCH ID: 2 RGB: 8, 8, 8 Alpha: 8 Depth: 24 Stencil: 8 // BAD MATCH ID: 3 RGB: 8, 8, 8 Alpha: 8 Depth: 24 Stencil: 8 // BAD MATCH ID: 4 RGB: 8, 8, 8 Alpha: 8 Depth: 0 Stencil: 0 // BAD MATCH ID: 5 RGB: 8, 8, 8 Alpha: 8 Depth: 24 Stencil: 8 // BAD MATCH ID: 6 RGB: 5, 6, 5 Alpha: 0 Depth: 24 Stencil: 8 ID: 7 RGB: 5, 6, 5 Alpha: 0 Depth: 0 Stencil: 0 ID: 8 RGB: 5, 6, 5 Alpha: 0 Depth: 24 Stencil: 8 Clearly, all configurations with 32-bit color depth fail and all 16-bit ones are OK but: 1. Why? 2. WHY?! :) 3. How do I tell which ones would fail before actually trying to use them? The code below is as simple as it can get. I put if (v[0] == 6) there to check different configs, normally they're chosen by half-clever config matcher :) private void createSurface(SurfaceHolder holder) { egl = (EGL10)EGLContext.getEGL(); eglDisplay = egl.eglGetDisplay(EGL10.EGL_DEFAULT_DISPLAY); egl.eglInitialize(eglDisplay, null); int[] numConfigs = new int[1]; egl.eglChooseConfig(eglDisplay, new int[] { EGL10.EGL_NONE }, null, 0, numConfigs); EGLConfig[] configs = new EGLConfig[numConfigs[0]]; egl.eglChooseConfig(eglDisplay, new int[] { EGL10.EGL_NONE }, configs, numConfigs[0], numConfigs); int[] v = new int[1]; for (EGLConfig c : configs) { egl.eglGetConfigAttrib(eglDisplay, c, EGL10.EGL_CONFIG_ID, v); if (v[0] == 6) { eglConfig = c; } } eglContext = egl.eglCreateContext(eglDisplay, eglConfig, EGL10.EGL_NO_CONTEXT, null); if (eglContext == null || eglContext == EGL10.EGL_NO_CONTEXT) { throw new RuntimeException("Unable to create EGL context"); } eglSurface = egl.eglCreateWindowSurface(eglDisplay, eglConfig, holder, null); if (eglSurface == null || eglSurface == EGL10.EGL_NO_SURFACE) { throw new RuntimeException("Unable to create EGL surface"); } if (!egl.eglMakeCurrent(eglDisplay, eglSurface, eglSurface, eglContext)) { throw new RuntimeException("Unable to make EGL current"); } gl = (GL10)eglContext.getGL(); }

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• get contact info from android contact picker

  - by ng93

  hi im trying to call the contact picker, get the persons name, phone and e-mail into strings and send them to another activity using an intent. So far this works Intent intent = new Intent(Intent.ACTION_PICK, ContactsContract.Contacts.CONTENT_URI); startActivityForResult(intent, 1); @Override public void onActivityResult(int reqCode, int resultCode, Intent data) { super.onActivityResult(reqCode, resultCode, data); if (resultCode == Activity.RESULT_OK) { Uri contactData = data.getData(); Cursor c = managedQuery(contactData, null, null, null, null); if (c.moveToFirst()) { String name = c.getString(c.getColumnIndexOrThrow(ContactsContract.Contacts.DISPLAY_NAME)); Intent intent = new Intent(CurrentActivity.this, NewActivity.class); intent.putExtra("name", name); startActivityForResult(intent, 0); } } } but if i add in: String number = c.getString(c.getColumnIndexOrThrow(ContactsContract.CommonDataKinds.Phone.NUMBER)); it force closes maybe theres another way to get their number? thanks for help, ng93

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• Fill spinner from cursor in android

  - by Rickard

  Hi, i have searched for a awnser for this for a while today. It all looks so easy but i never get it to work. I want to fill a spinner with my cursor. I have been trying to use SimpleCursorAdapter for this as a lot of sites say i shall but i never get it to work. Show me just how easy it is :) Thanks for your time! My cursor Cursor cursor = db.query(DATABASE_TABLE_Clients, new String[] {"_id", "C_Name"}, null, null, null, null, "C_Name"); My spinner (Spinner) findViewById(R.id.spnClients); My Code Cursor cursor_Names = SQLData.getClientNames(); startManagingCursor(cursor_Names); String[] columns = new String[] { "C_Name" }; int[] to = new int[] { R.id.txt_Address }; SimpleCursorAdapter mAdapter = new SimpleCursorAdapter(this, android.R.layout.simple_spinner_dropdown_item, cursor_Names, columns, to); Spinner spnClients = (Spinner) findViewById(R.id.spnClients); spnClients.setAdapter(mAdapter);

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• Creating a Dynamic DataRow for easier DataRow Syntax

  - by Rick Strahl

  I've been thrown back into an older project that uses DataSets and DataRows as their entity storage model. I have several applications internally that I still maintain that run just fine (and I sometimes wonder if this wasn't easier than all this ORM crap we deal with with 'newer' improved technology today - but I disgress) but use this older code. For the most part DataSets/DataTables/DataRows are abstracted away in a pseudo entity model, but in some situations like queries DataTables and DataRows are still surfaced to the business layer. Here's an example. Here's a business object method that runs dynamic query and the code ends up looping over the result set using the ugly DataRow Array syntax:public int UpdateAllSafeTitles() { int result = this.Execute("select pk, title, safetitle from " + Tablename + " where EntryType=1", "TPks"); if (result < 0) return result; result = 0; foreach (DataRow row in this.DataSet.Tables["TPks"].Rows) { string title = row["title"] as string; string safeTitle = row["safeTitle"] as string; int pk = (int)row["pk"]; string newSafeTitle = this.GetSafeTitle(title); if (newSafeTitle != safeTitle) { this.ExecuteNonQuery("update " + this.Tablename + " set safeTitle=@safeTitle where pk=@pk", this.CreateParameter("@safeTitle",newSafeTitle), this.CreateParameter("@pk",pk) ); result++; } } return result; } The problem with looping over DataRow objecs is two fold: The array syntax is tedious to type and not real clear to look at, and explicit casting is required in order to do anything useful with the values. I've highlighted the place where this matters. Using the DynamicDataRow class I'll show in a minute this code can be changed to look like this:public int UpdateAllSafeTitles() { int result = this.Execute("select pk, title, safetitle from " + Tablename + " where EntryType=1", "TPks"); if (result < 0) return result; result = 0; foreach (DataRow row in this.DataSet.Tables["TPks"].Rows) { dynamic entry = new DynamicDataRow(row); string newSafeTitle = this.GetSafeTitle(entry.title); if (newSafeTitle != entry.safeTitle) { this.ExecuteNonQuery("update " + this.Tablename + " set safeTitle=@safeTitle where pk=@pk", this.CreateParameter("@safeTitle",newSafeTitle), this.CreateParameter("@pk",entry.pk) ); result++; } } return result; } The code looks much a bit more natural and describes what's happening a little nicer as well. Well, using the new dynamic features in .NET it's actually quite easy to implement the DynamicDataRow class. Creating your own custom Dynamic Objects .NET 4.0 introduced the Dynamic Language Runtime (DLR) and opened up a whole bunch of new capabilities for .NET applications. The dynamic type is an easy way to avoid Reflection and directly access members of 'dynamic' or 'late bound' objects at runtime. There's a lot of very subtle but extremely useful stuff that dynamic does (especially for COM Interop scenearios) but in its simplest form it often allows you to do away with manual Reflection at runtime. In addition you can create DynamicObject implementations that can perform  custom interception of member accesses and so allow you to provide more natural access to more complex or awkward data structures like the DataRow that I use as an example here. Bascially you can subclass DynamicObject and then implement a few methods (TryGetMember, TrySetMember, TryInvokeMember) to provide the ability to return dynamic results from just about any data structure using simple property/method access. In the code above, I created a custom DynamicDataRow class which inherits from DynamicObject and implements only TryGetMember and TrySetMember. Here's what simple class looks like:/// <summary> /// This class provides an easy way to turn a DataRow /// into a Dynamic object that supports direct property /// access to the DataRow fields. /// /// The class also automatically fixes up DbNull values /// (null into .NET and DbNUll to DataRow) /// </summary> public class DynamicDataRow : DynamicObject { /// <summary> /// Instance of object passed in /// </summary> DataRow DataRow; /// <summary> /// Pass in a DataRow to work off /// </summary> /// <param name="instance"></param> public DynamicDataRow(DataRow dataRow) { DataRow = dataRow; } /// <summary> /// Returns a value from a DataRow items array. /// If the field doesn't exist null is returned. /// DbNull values are turned into .NET nulls. /// /// </summary> /// <param name="binder"></param> /// <param name="result"></param> /// <returns></returns> public override bool TryGetMember(GetMemberBinder binder, out object result) { result = null; try { result = DataRow[binder.Name]; if (result == DBNull.Value) result = null; return true; } catch { } result = null; return false; } /// <summary> /// Property setter implementation tries to retrieve value from instance /// first then into this object /// </summary> /// <param name="binder"></param> /// <param name="value"></param> /// <returns></returns> public override bool TrySetMember(SetMemberBinder binder, object value) { try { if (value == null) value = DBNull.Value; DataRow[binder.Name] = value; return true; } catch {} return false; } } To demonstrate the basic features here's a short test: [TestMethod] [ExpectedException(typeof(RuntimeBinderException))] public void BasicDataRowTests() { DataTable table = new DataTable("table"); table.Columns.Add( new DataColumn() { ColumnName = "Name", DataType=typeof(string) }); table.Columns.Add( new DataColumn() { ColumnName = "Entered", DataType=typeof(DateTime) }); table.Columns.Add(new DataColumn() { ColumnName = "NullValue", DataType = typeof(string) }); DataRow row = table.NewRow(); DateTime now = DateTime.Now; row["Name"] = "Rick"; row["Entered"] = now; row["NullValue"] = null; // converted in DbNull dynamic drow = new DynamicDataRow(row); string name = drow.Name; DateTime entered = drow.Entered; string nulled = drow.NullValue; Assert.AreEqual(name, "Rick"); Assert.AreEqual(entered,now); Assert.IsNull(nulled); // this should throw a RuntimeBinderException Assert.AreEqual(entered,drow.enteredd); } The DynamicDataRow requires a custom constructor that accepts a single parameter that sets the DataRow. Once that's done you can access property values that match the field names. Note that types are automatically converted - no type casting is needed in the code you write. The class also automatically converts DbNulls to regular nulls and vice versa which is something that makes it much easier to deal with data returned from a database. What's cool here isn't so much the functionality - even if I'd prefer to leave DataRow behind ASAP -  but the fact that we can create a dynamic type that uses a DataRow as it's 'DataSource' to serve member values. It's pretty useful feature if you think about it, especially given how little code it takes to implement. By implementing these two simple methods we get to provide two features I was complaining about at the beginning that are missing from the DataRow: Direct Property Syntax Automatic Type Casting so no explicit casts are required Caveats As cool and easy as this functionality is, it's important to understand that it doesn't come for free. The dynamic features in .NET are - well - dynamic. Which means they are essentially evaluated at runtime (late bound). Rather than static typing where everything is compiled and linked by the compiler/linker, member invokations are looked up at runtime and essentially call into your custom code. There's some overhead in this. Direct invocations - the original code I showed - is going to be faster than the equivalent dynamic code. However, in the above code the difference of running the dynamic code and the original data access code was very minor. The loop running over 1500 result records took on average 13ms with the original code and 14ms with the dynamic code. Not exactly a serious performance bottleneck. One thing to remember is that Microsoft optimized the DLR code significantly so that repeated calls to the same operations are routed very efficiently which actually makes for very fast evaluation. The bottom line for performance with dynamic code is: Make sure you test and profile your code if you think that there might be a performance issue. However, in my experience with dynamic types so far performance is pretty good for repeated operations (ie. in loops). While usually a little slower the perf hit is a lot less typically than equivalent Reflection work. Although the code in the second example looks like standard object syntax, dynamic is not static code. It's evaluated at runtime and so there's no type recognition until runtime. This means no Intellisense at development time, and any invalid references that call into 'properties' (ie. fields in the DataRow) that don't exist still cause runtime errors. So in the case of the data row you still get a runtime error if you mistype a column name:// this should throw a RuntimeBinderException Assert.AreEqual(entered,drow.enteredd); Dynamic - Lots of uses The arrival of Dynamic types in .NET has been met with mixed emotions. Die hard .NET developers decry dynamic types as an abomination to the language. After all what dynamic accomplishes goes against all that a static language is supposed to provide. On the other hand there are clearly scenarios when dynamic can make life much easier (COM Interop being one place). Think of the possibilities. What other data structures would you like to expose to a simple property interface rather than some sort of collection or dictionary? And beyond what I showed here you can also implement 'Method missing' behavior on objects with InvokeMember which essentially allows you to create dynamic methods. It's all very flexible and maybe just as important: It's easy to do. There's a lot of power hidden in this seemingly simple interface. Your move…© Rick Strahl, West Wind Technologies, 2005-2011Posted in CSharp  .NET   Tweet (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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