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  • Converting VB .NET code to C#

    - by Brono The Vibrator
    I have the follwing VB .NET code I am trying to convert to C# Dim decryptedBytes(CInt(encryptedStream.Length - 1)) As Byte I tried this: int tempData = Convert.ToInt32(encryptedStream.Length - 1); Byte decryptedBytes; decryptedBytes = decryptedBytes[tempData]; but got this error message: Cannot apply indexing with [] to an expression of type byte. Please note that the VB .NET code works.

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  • Sending jpegs by tcp socket...sometimes incomplete.

    - by Guy
    Vb.net Hi I've been working on a project for months now (vb 2008 express). There is one final problem which I can't solve. I need to send images to a client from a 'server'(listener). The code below works most of the time but sometimes the image is incomplete. I believe this might be something to do with the tcp packet sizes varying, maybe limited by how busy it is out there on the net. I have seen examples of code that splits the image into chunks and sends them out, but I can't get them to work maybe because I'm using a different vb version. The pictures to be sent are small 20k max. Any working code examples would be wonderful. I have been experimenting and failing with this final hurdle for weeks. Thanks in anticipation. Client----- Sub GetPic() '------- Connect to Server ClientSocket = New Socket(AddressFamily.InterNetwork, SocketType.Stream, _ ProtocolType.Tcp) ClientSocket.Connect(Epoint) '------- Send Picture Request Dim Bytes() As Byte = System.Text.ASCIIEncoding.ASCII.GetBytes("Send Picture") ClientSocket.Send(Bytes, Bytes.Length, SocketFlags.None) '------- Receive Response Dim RecvBuffer(20000) As Byte Dim Numbytes As Integer Numbytes = ClientSocket.Receive(RecvBuffer) Dim Darray(Numbytes) As Byte Buffer.BlockCopy(RecvBuffer, 0, Darray, 0, Numbytes) '------- Close Connection ClientSocket.Shutdown(SocketShutdown.Both) ClientSocket.Close() '------- Dim MStrm = New MemoryStream(Darray) Picture = Image.FromStream(MStrm) End Sub Listener----- 'Threaded from a listener Sub ClientThread(ByVal Client As TcpClient) Dim MStrm As New MemoryStream Dim Rbuffer(1024) As Byte Dim Tbyte As Byte() Dim NStrm As NetworkStream = Client.GetStream() Dim I As Integer = NStrm.Read(Rbuffer, 0, Rbuffer.Length) Dim Incoming As String = System.Text.Encoding.ASCII.GetString(Rbuffer, 0, I) If Incoming = "Send Picture" then Picture Save(MStrm, Picture.RawFormat) Tbyte = MStrm.ToArray NStrm.Write(Tbyte, 0, Tbyte.Length) End if Client.Close() End Sub

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  • Call HttpWebRequest in another thread as UI with Task class - avoid to dispose object created in Task scope

    - by John
    I would like call HttpWebRequest on another thread as UI, because I must make 200 request or server and downloaded image. My scenation is that I make a request on server, create image and return image. This I make in another thread. I use Task class, but it call automaticaly Dispose method on all object created in task scope. So I return null object from this method. public BitmapImage CreateAvatar(Uri imageUri, int sex) { if (imageUri == null) return CreateDefaultAvatar(sex); BitmapImage image = null; new Task(() => { var request = WebRequest.Create(imageUri); var response = request.GetResponse(); using (var stream = response.GetResponseStream()) { Byte[] buffer = new Byte[response.ContentLength]; int offset = 0, actuallyRead = 0; do { actuallyRead = stream.Read(buffer, offset, buffer.Length - offset); offset += actuallyRead; } while (actuallyRead > 0); image = new BitmapImage { CreateOptions = BitmapCreateOptions.None, CacheOption = BitmapCacheOption.OnLoad }; image.BeginInit(); image.StreamSource = new MemoryStream(buffer); image.EndInit(); image.Freeze(); } }).Start(); return image; } How avoid it? Thank Mr. Jon Skeet try this: private Stream GetImageStream(Uri imageUri) { Byte[] buffer = null; //new Task(() => //{ var request = WebRequest.Create(imageUri); var response = request.GetResponse(); using (var stream = response.GetResponseStream()) { buffer= new Byte[response.ContentLength]; int offset = 0, actuallyRead = 0; do { actuallyRead = stream.Read(buffer, offset, buffer.Length - offset); offset += actuallyRead; } while (actuallyRead > 0); } //}).Start(); return new MemoryStream(buffer); } It return object which is null a than try this: private Stream GetImageStream(Uri imageUri) { Byte[] buffer = null; new Task(() => { var request = WebRequest.Create(imageUri); var response = request.GetResponse(); using (var stream = response.GetResponseStream()) { buffer= new Byte[response.ContentLength]; int offset = 0, actuallyRead = 0; do { actuallyRead = stream.Read(buffer, offset, buffer.Length - offset); offset += actuallyRead; } while (actuallyRead > 0); } }).Start(); return new MemoryStream(buffer); } Method above return null

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  • Java Apache Commons users

    - by Tom Brito
    Is there anything in apache commons to convert a Object to byte array, like the following method does? public static byte[] toByteArray(Object obj) throws IOException { ByteArrayOutputStream baos = new ByteArrayOutputStream(); ObjectOutputStream oos = new ObjectOutputStream(baos); oos.writeObject(obj); oos.flush(); byte[] data = baos.toByteArray(); return data; } [try-finally block closing buffers were omitted to simplify]

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  • Save binarydata into a image file in c# / silverlight 3

    - by Jin
    byte[] binaryData = new Byte[pngStream.Length]; long bytesRead = pngStream.Read(binaryData, 0, (int)pngStream.Length); string base64String = System.Convert.ToBase64String(binaryData, 0, binaryData.Length); I have a binary data in Byte array. Does anybody know how to save this into any image file (png or jpg) in silverlight3 or c#? Thanks

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  • POST variables to web server?

    - by OverTheRainbow
    Hello I've been trying several things from Google to POST data to a web server, but none of them work: I'm still stuck at how to convert the variables into the request, considering that the second variable is an SQL query so it has spaces. Does someone know the correct way to use a WebClient to POST data? I'd rather use WebClient because it requires less code than HttpWebRequest/HttpWebResponse. Here's what I tried so far: Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim wc = New WebClient() 'convert data wc.Headers.Add("Content-Type", "application/x-www-form-urlencoded") Dim postData = String.Format("db={0}&query={1}", _ HttpUtility.UrlEncode("books.sqlite"), _ HttpUtility.UrlEncode("SELECT id,title FROM boooks")) 'Dim bytArguments As Byte() = Encoding.ASCII.GetBytes("db=books.sqlite|query=SELECT * FROM books") 'POST query Dim bytRetData As Byte() = wc.UploadData("http://localhost:9999/get", "POST", postData) RichTextBox1.Text = Encoding.ASCII.GetString(bytRetData) Exit Sub Dim client = New WebClient() Dim nv As New Collection nv.Add("db", "books.sqlite") nv.Add("query", "SELECT id,title FROM books") Dim address As New Uri("http://localhost:9999/get") 'Dim bytRetData As Byte() = client.UploadValues(address, "POST", nv) RichTextBox1.Text = Encoding.ASCII.GetString(bytRetData) Exit Sub 'Dim wc As New WebClient() 'convert data wc.Headers.Add("Content-Type", "application/x-www-form-urlencoded") Dim bytArguments As Byte() = Encoding.ASCII.GetBytes("db=books.sqlite|query=SELECT * FROM books") 'POST query 'Dim bytRetData As Byte() = wc.UploadData("http://localhost:9999/get", "POST", bytArguments) RichTextBox1.Text = Encoding.ASCII.GetString(bytRetData) Exit Sub End Sub Thank you.

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  • How to generate a cryptographically secure Double between 0 and 1?

    - by Portman
    I know how to generate a random number between 0 and 1 using the NextDouble method of the pseudo-random number generator. var rng1 = new System.Random(); var random1 = rng1.NextDouble(); // generates a random double between 0 and 1.0 And I know how to fill a random byte array using the cryptographically secure random number generator. Byte[] bytes = new Byte[8]; var rng2 = new System.Security.Cryptography.RNGCryptoServiceProvider(); rng2.GetBytes(bytes); // generates 8 random bytes But how can I convert the byte-array output of RNGCryptoServiceProvider into a random number between 0 (inclusive) and 1 (exclusive)?

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  • DataType for storing a long serial number (10 bytes)

    - by CrimsonX
    We have a device which has a 10 byte serial number which must be read into our application and stored into a .net datatype. In the device it is stored as an unsigned 10-byte (80-bit) number. I don't expect we will be performing any mathematical operations on this number, but only displaying it to the user. The .NET framework doesn't have a built in UNIT128 to store this datatype. My suggestion for storing this datatype is to create a 10 element byte array and read in the data into this array. Are there any better solutions to this problem? Note: I have seen in this question that a GUID is a 128 byte signed integer, but it seems like a bad idea to use a GUID in this fashion. Any other suggestions?

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  • Hash Digest / Array Comparison in C#

    - by Erik Karulf
    Hi All, I'm writing an application that needs to verify HMAC-SHA256 checksums. The code I currently have looks something like this: static bool VerifyIntegrity(string secret, string checksum, string data) { // Verify HMAC-SHA256 Checksum byte[] key = System.Text.Encoding.UTF8.GetBytes(secret); byte[] value = System.Text.Encoding.UTF8.GetBytes(data); byte[] checksum_bytes = System.Text.Encoding.UTF8.GetBytes(checksum); using (var hmac = new HMACSHA256(key)) { byte[] expected_bytes = hmac.ComputeHash(value); return checksum_bytes.SequenceEqual(expected_bytes); } } I know that this is susceptible to timing attacks. Is there a message digest comparison function in the standard library? I realize I could write my own time hardened comparison method, but I have to believe that this is already implemented elsewhere.

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  • P0ST variables to web server?

    - by OverTheRainbow
    Hello I've been trying several things from Google to POST data to a web server, but none of them work: I'm still stuck at how to convert the variables into the request, considering that the second variable is an SQL query so it has spaces. Does someone know the correct way to use a WebClient to POST data? I'd rather use WebClient because it requires less code than HttpWebRequest/HttpWebResponse. Here's what I tried so far: Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim wc = New WebClient() 'convert data wc.Headers.Add("Content-Type", "application/x-www-form-urlencoded") Dim postData = String.Format("db={0}&query={1}", _ HttpUtility.UrlEncode("books.sqlite"), _ HttpUtility.UrlEncode("SELECT id,title FROM boooks")) 'Dim bytArguments As Byte() = Encoding.ASCII.GetBytes("db=books.sqlite|query=SELECT * FROM books") 'POST query Dim bytRetData As Byte() = wc.UploadData("http://localhost:9999/get", "POST", postData) RichTextBox1.Text = Encoding.ASCII.GetString(bytRetData) Exit Sub Dim client = New WebClient() Dim nv As New Collection nv.Add("db", "books.sqlite") nv.Add("query", "SELECT id,title FROM books") Dim address As New Uri("http://localhost:9999/get") 'Dim bytRetData As Byte() = client.UploadValues(address, "POST", nv) RichTextBox1.Text = Encoding.ASCII.GetString(bytRetData) Exit Sub 'Dim wc As New WebClient() 'convert data wc.Headers.Add("Content-Type", "application/x-www-form-urlencoded") Dim bytArguments As Byte() = Encoding.ASCII.GetBytes("db=books.sqlite|query=SELECT * FROM books") 'POST query 'Dim bytRetData As Byte() = wc.UploadData("http://localhost:9999/get", "POST", bytArguments) RichTextBox1.Text = Encoding.ASCII.GetString(bytRetData) Exit Sub End Sub Thank you.

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  • php and asp problem in uploading

    - by moustafa
    i have an ASP web services to change byte array that given from the client and change it to a file and save it in the web server the code is like this : [WebMethod] public string UploadFile(byte[] f, string fileName) { try { MemoryStream ms = new MemoryStream(f); String path="/myfile/"; String location=HttpContext.Current.Server.MapPath(path); FileStream fs = new FileStream(HttpContext.Current.Server.MapPath(path)+fileName, FileMode.Create); ms.WriteTo(fs); ms.Close(); fs.Close(); return "OK"; } catch (Exception ex) { return ex.Message.ToString(); } } the web services need byte array and file name.. i build the client in php upload.php the code is <html> <body> <form action="action1.php" method="post" enctype="multipart/form-data"> Pilih File Anda: <input type="file" name="myfile" /> <input type="submit" value="Upload" /> </form> </body> <html> and action1.php the code is: <?php require_once('nusoap.php'); $client = new nusoap_client('http://192.168.254.160/testuploadah/FileUploader.asmx?WSDL', 'wsdl','','', '', ''); $err = $client->getError(); if ($err) { echo '<h2>Constructor error</h2><pre>' . $err . '</pre>'; } if(is_uploaded_file($_FILES['myfile']['tmp_name'])){ $uploadFile = $_FILES['myfile']; ////how can read byte array of $uploadFile so i can send to web services??? ////are php only can send array or string ? $params[]->f=??????????????? $params[]->fileName=$_FILES['myfile']['name']; $result = $client->call('UploadFile', $params,'', '', false, true); if ($client->fault) { echo '<h2>Fault</h2><pre>'; print_r($result); echo '</pre>'; } else { //Check for errors $err = $client->getError(); if ($err) { //// Display the error echo '<h2>Error</h2><pre>' . $err . '</pre>'; } else { //// Display the result echo '<h2>Result</h2><pre>'; print_r($result); echo '</pre>'; } } } ?> how can i Send the byte array parameter to the web services,so the web services can started???? i still can resolve this problem,the web services always return an error because i can't send byte array

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  • RSA encryption/ Decryption in a client server application

    - by user308806
    Hi guys, probably missing something very straight forward on this, but please forgive me, I'm very naive! Have a client server application where the client identifies its self with an RSA encrypted username & password. Unfortunately I'm getting a "bad padding exception: data must start with zero" when i try to decrypt with the public key on the client side. I'm fairly sure the key is correct as I have tested encrypting with public key then decrypting with private key on the client side with no problems at all. Just seems when I transfer it over the connection it messses it up somehow?! Using PrintWriter & BufferedReader on the sockets if thats of importance. EncodeBASE64 & DecodeBASE64 encode byte[] to 64base and vice versa respectively. Any ideas guys?? Client side: Socket connectionToServer = new Socket("127.0.0.1", 7050); InputStream in = connectionToServer.getInputStream(); DataInputStream dis = new DataInputStream(in); int length = dis.readInt(); byte[] data = new byte[length]; // dis.readFully(data); dis.read(data); System.out.println("The received Data*****************************************"); System.out.println("The length of bits "+ length); System.out.println(data); System.out.println("***********************************************************"); Decryption d = new Decryption(); byte [] ttt = d.decrypt(data); System.out.print(data); String ss = new String(ttt); System.out.println("***********************"); System.out.println(ss); System.out.println("************************"); Server Side: in = connectionFromClient.getInputStream(); OutputStream out = connectionFromClient.getOutputStream(); DataOutputStream dataOut = new DataOutputStream(out); LicenseList licenses = new LicenseList(); String ValidIDs = licenses.getAllIDs(); System.out.println(ValidIDs); Encryption enc = new Encryption(); byte[] encrypted = enc.encrypt(ValidIDs); byte[] dd = enc.encrypt(ValidIDs); String tobesent = new String(dd); //byte[] rsult = enc.decrypt(dd); //String tt = String(rsult); System.out.println("The sent data**********************************************"); System.out.println(dd); String temp = new String(dd); System.out.println(temp); System.out.println("*************************************************************"); //BufferedWriter bf = new BufferedWriter(OutputStreamWriter(out)); //dataOut.write(ValidIDs.getBytes().length); dataOut.writeInt(ValidIDs.getBytes().length); dataOut.flush(); dataOut.write(encrypted); dataOut.flush(); System.out.println("********Testing**************"); System.out.println("Here are the ids:::"); System.out.println(licenses.getAllIDs()); System.out.println("**********************"); //bw.write("it is working well\n");

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  • Java equivalent of the VB Request.InputStream

    - by Android Addict
    I have a web service that I am re-writing from VB to a Java servlet. In the web service, I want to extract the body entity set on the client-side as such: StringEntity stringEntity = new StringEntity(xml, HTTP.UTF_8); stringEntity.setContentType("application/xml"); httppost.setEntity(stringEntity); In the VB web service, I get this data by using: Dim objReader As System.IO.StreamReader objReader = New System.IO.StreamReader(Request.InputStream) Dim strXML As String = objReader.ReadToEnd and this works great. But I am looking for the equivalent in Java. I have tried this: ServletInputStream dataStream = req.getInputStream(); byte[] data = new byte[dataStream.toString().length()]; dataStream.read(data); but all it gets me is an unintelligible string: data = [B@68514fec Please advise. Edit Per the answers, I have tried: ServletInputStream dataStream = req.getInputStream(); ByteArrayOutputStream buffer = new ByteArrayOutputStream(); int r; byte[] data = new byte[1024*1024]; while ((r = dataStream.read(data, 0, data.length)) != -1) { buffer.write(data, 0, r); } buffer.flush(); byte[] data2 = buffer.toByteArray(); System.out.println("DATA = "+Arrays.toString(data2)); whichs yields: DATA = [] and when I try: System.out.println("DATA = "+data2.toString()); I get: DATA = [B@15282c7f So what am I doing wrong? As stated earlier, the same call to my VB service gives me the xml that I pass in.

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  • Detection of negative integers using bit operations

    - by Nawaz
    One approach to check if a given integer is negative or not, could be this: (using bit operations) int num_bits = sizeof(int) * 8; //assuming 8 bits per byte! int sign_bit = given_int & (1 << (num_bits-1)); //sign_bit is either 1 or 0 if ( sign_bit ) { cout << "given integer is negative"<<endl; } else { cout << "given integer is positive"<<endl; } The problem with this solution is that number of bits per byte couldn't be 8, it could be 9,10, 11 even 16 or 40 bits per byte. Byte doesn't necessarily mean 8 bits! Anyway, this problem can be easily fixed by writing, //CHAR_BIT is defined in limits.h int num_bits = sizeof(int) * CHAR_BIT; //no assumption. It seems fine now. But is it really? Is this Standard conformant? What if the negative integer is not represented as 2's complement? What if it's representation in a binary numeration system that doesn't necessitate only negative integers to have 1 in it's most significant bit? Can we write such code that will be both portable and standard conformant? Related topics: Size of Primitive data types Why is a boolean 1 byte and not 1 bit of size?

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  • How do I patch a Windows API at runtime so that it to returns 0 in x64?

    - by Jorge Vasquez
    In x86, I get the function address using GetProcAddress() and write a simple XOR EAX,EAX; RET; in it. Simple and effective. How do I do the same in x64? bool DisableSetUnhandledExceptionFilter() { const BYTE PatchBytes[5] = { 0x33, 0xC0, 0xC2, 0x04, 0x00 }; // XOR EAX,EAX; RET; // Obtain the address of SetUnhandledExceptionFilter HMODULE hLib = GetModuleHandle( _T("kernel32.dll") ); if( hLib == NULL ) return false; BYTE* pTarget = (BYTE*)GetProcAddress( hLib, "SetUnhandledExceptionFilter" ); if( pTarget == 0 ) return false; // Patch SetUnhandledExceptionFilter if( !WriteMemory( pTarget, PatchBytes, sizeof(PatchBytes) ) ) return false; // Ensures out of cache FlushInstructionCache(GetCurrentProcess(), pTarget, sizeof(PatchBytes)); // Success return true; } static bool WriteMemory( BYTE* pTarget, const BYTE* pSource, DWORD Size ) { // Check parameters if( pTarget == 0 ) return false; if( pSource == 0 ) return false; if( Size == 0 ) return false; if( IsBadReadPtr( pSource, Size ) ) return false; // Modify protection attributes of the target memory page DWORD OldProtect = 0; if( !VirtualProtect( pTarget, Size, PAGE_EXECUTE_READWRITE, &OldProtect ) ) return false; // Write memory memcpy( pTarget, pSource, Size ); // Restore memory protection attributes of the target memory page DWORD Temp = 0; if( !VirtualProtect( pTarget, Size, OldProtect, &Temp ) ) return false; // Success return true; } This example is adapted from code found here: http://www.debuginfo.com/articles/debugfilters.html#overwrite .

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  • C 64-bit Pointer Alignment

    - by DuneBug
    Are pointers on a 64-bit system still 4 byte aligned (similar to a double on a 32 bit system)? Or are they note 8 byte aligned? For example, on a 64-bit system how big is the following data structure: struct a { void* ptr; char myChar; } Would the pointer by 8 byte aligned, causing 7 bytes of padding for the character (total = 8 + 8 = 16)? Or would the pointer be 4 byte aligned (4 bytes + 4 bytes) causing 3 bytes of padding (total = 4 + 4 + 4 = 12)? Thanks, Ryan

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  • JNI Stream binary data from C++ to Java

    - by Cliff
    I need help passing binary data into Java. I'm trying to use jbytearray but when the data gets into Java it appears corrupt. Can somebody give me a hand? Here's a snip of some example code. First the native C++ side: printf("Building audio array copy\n"); jbyteArray rawAudioCopy = env-NewByteArray(10); jbyte toCopy[10]; printf("Filling audio array copy\n"); char theBytes[10] = {0,1,2,3,4,5,6,7,8,9}; for (int i = 0; i < sizeof(theBytes); i++) { toCopy[i] = theBytes[i]; } env->SetByteArrayRegion(rawAudioCopy,0,10,toCopy); printf("Finding object callback\n"); jmethodID aMethodId = env->GetMethodID(env->GetObjectClass(obj),"handleAudio","([B)V"); if(0==aMethodId) throw MyRuntimeException("Method not found error",99); printf("Invoking the callback\n"); env->CallVoidMethod(obj,aMethodId, &rawAudioCopy); and then the Java callback method: public void handleAudio(byte[] audio){ System.out.println("Audio supplied to Java [" + audio.length + "] bytes"); byte[] expectedAudio = {0,1,2,3,4,5,6,7,8,9}; for (int i = 0; i < audio.length; i++) { if(audio[i]!= expectedAudio[i]) System.err.println("Expected byte " + expectedAudio[i] + " at byte " + i + " but got byte " + audio[i]); else System.out.print('.'); } System.out.println("Audio passed back accordingly!"); } I get the following output when the callback is invoked: library loaded! Audio supplied to Java [-2019659176] bytes Audio passed back accordingly!

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  • wireless profile saving problem please help me out

    - by Jayjitraj
    DATA_BLOB in; DATA_BLOB out; BYTE pin=(BYTE)"FIPL2"; DWORD din=strlen((char*)pin)+1; in.pbData = pin; in.cbData = din; if(CryptProtectData(&in,L"what is it",NULL,NULL,NULL,0,&out)) { BYTE *b=out.pbData; Now I want to convert it into hexadecimal to save as my wifi password so what should i do }

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  • retrieve image from sql server in picturebox

    - by user3116296
    I have saved a picture in sql server and now i can not to retrieve image and set it's in picturebox with linq. why byte[] x become null? private void dataGridViewUser_CellClick(object sender, DataGridViewCellEventArgs e) { DataGridViewRow row = dataGridViewUser.CurrentRow; byte[] x=(byte[])row.Cells["Image"].Value; MemoryStream ms1 = new MemoryStream(x); picuser.Image = Bitmap.FromStream(ms1); }

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  • Naudio - putting audio stream into values [-1,1]

    - by denonth
    Hi all I need to put my audio stream into values of [-1,1]. Can someone tell me a good approach. I was reading byte array and float array from stream but I don't know what to do next. Here is my code: float[] bytes=new float[stream.Length]; float biggest= 0; for (int i = 0; i < stream.Length; i++) { bytes[i] = (byte)stream.ReadByte(); if (bytes[i] > biggest) { biggest=bytes[i]; } } and I don't know how to put values into stream. Because byte is only positive values. And I need to have from [-1,1] for (int i = 0; i < bytes.Count(); i++) { bytes[i] = (byte)(bytes[i] * (1 / biggest)); }

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  • Dealing with array of IntPtr

    - by Padu Merloti
    I think I'm close and I bet the solution is something stupid. I have a C++ native DLL where I define the following function: DllExport bool __stdcall Open(const char* filePath, int *numFrames, void** data); { //creates the list of arrays here... don't worry, lifetime is managed somewhere else //foreach item of the list: { BYTE* pByte = GetArray(i); //here's where my problem lives *(data + i * sizeofarray) = pByte; } *numFrames = total number of items in the list return true; } Basically, given a file path, this function creates a list of byte arrays (BYTE*) and should return a list of pointers via the data param. Each pointing to a different byte array. I want to pass an array of IntPtr from C# and be able to marshal each individual array in order. Here's the code I'm using: [DllImport("mydll.dll",EntryPoint = "Open")] private static extern bool MyOpen( string filePath, out int numFrames, out IntPtr[] ptr); internal static bool Open( string filePath, out int numFrames, out Bitmap[] images) { var ptrList = new IntPtr[512]; MyOpen(filePath, out numFrames, out ptrList); images = new Bitmap[numFrames]; var len = 100; //for sake of simplicity for (int i=0; i<numFrames;i++) { var buffer = new byte[len]; Marshal.Copy(ptrList[i], buffer, 0, len); images[i] = CreateBitmapFromBuffer(buffer, height, width); } return true; } Problem is in my C++ code. When I assign *(data + i * sizeofarray) = pByte; it corrupts the array of pointers... what am I doing wrong?

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  • Negative number representation across multiple architechture

    - by Donotalo
    I'm working with OKI 431 micro controller. It can communicate with PC with appropriate software installed. An EEPROM is connected in the I2C bus of the micro which works as permanent memory. The PC software can read from and write to this EEPROM. Consider two numbers, B and C, each is two byte integer. B is known to both the PC software and the micro and is a constant. C will be a number so close to B such that B-C will fit in a signed 8 bit integer. After some testing, appropriate value for C will be determined by PC and will be stored into the EEPROM of the micro for later use. Now the micro can store C in two ways: The micro can store whole two byte representing C The micro can store B-C as one byte signed integer, and can later derive C from B and B-C I think that two's complement representation of negative number is now universally accepted by hardware manufacturers. Still I personally don't like negative numbers to be stored in a storage medium which will be accessed by two different architectures because negative number can be represented in different ways. For you information, 431 also uses two's complement. Should I get rid of the headache that negative number can be represented in different ways and accept the one byte solution as my other team member suggested? Or should I stick to the decision of the two byte solution because I don't need to deal with negative numbers? Which one would you prefer and why?

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  • .NET SerialPort.Read skipps bytes

    - by Lukas Rieger
    Solution Reading the data byte wise via "port.ReadByte" is too slow, the problem is inside the SerialPort class. i changed it to reading bigger chunks via "port.Read" and there are now no buffer overruns. although i found the solution myself, writing it down helped me and maybe someone else has the same problem and finds this via google... (how can i mark it as answered?) EDIT 2 by setting port.ReadBufferSize = 2000000; i can delay the problem for ~30 seconds. so it seems, .Net really is too slow... since my application is not that critical, i just set the buffer to 20MB, but i am still interested in the cause. EDIT i just tested something i had not thought of before (shame on me): port.ErrorReceived += (object self, SerialErrorReceivedEventArgs se_arg) => { Console.Write("| Error: {0} | ", System.Enum.GetName(se_arg.EventType.GetType(), se_arg.EventType)); }; and it seems that i have an overrun. Is the .Net implementation too slow for 500k or is there an error on my side? Original Question i built a very primitive oszilloscope (avr, which sends adc data over uart to an ftdi chip). On the pc side i have a WPF Programm that displays this data. The Protokoll is: two sync bytes (0xaffe) - 14 data bytes - two sync bytes - 14 data bytes - ... i use 16bit values, so inside the 14 data bytes are 7 channels (lsb first). I verified the uC Firmware with hTerm, and it does send and receive everything correct. But, if i try to read the data with C#, sometimes some bytes are lost. The oszilloscop programm is a mess, but i created a small sample application, which has the same symptoms. I added two extension methods to a) read one byte from the COM Port and ignore -1 (EOF) and b) wait for the sync pattern. The sample programm first syncs onto the data stream by waiting for (0xaffe) and then compares the received bytes with the expected values. the loop runs a few times until an assert failed message pops up. I could not find anything about lost bytes via google, any help would be appreciated. Code using System; using System.Collections.Generic; using System.Diagnostics; using System.IO.Ports; using System.Linq; using System.Text; using System.Threading.Tasks; namespace SerialTest { public static class SerialPortExtensions { public static byte ReadByteSerial(this SerialPort port) { int i = 0; do { i = port.ReadByte(); } while (i < 0 || i > 0xff); return (byte)i; } public static void WaitForPattern_Ushort(this SerialPort port, ushort pattern) { byte hi = 0; byte lo = 0; do { lo = hi; hi = port.ReadByteSerial(); } while (!(hi == (pattern >> 8) && lo == (pattern & 0x00ff))); } } class Program { static void Main(string[] args) { //500000 8n1 SerialPort port = new SerialPort("COM3", 500000, Parity.None, 8, StopBits.One); port.Open(); port.DiscardInBuffer(); port.DiscardOutBuffer(); //Sync port.WaitForPattern_Ushort(0xaffe); byte hi = 0; byte lo = 0; int val; int n = 0; // Start Loop, the stream is already synced while (true) { //Read 7 16-bit values (=14 Bytes) for (int i = 0; i < 7; i++) { lo = port.ReadByteSerial(); hi = port.ReadByteSerial(); val = ((hi << 8) | lo); Debug.Assert(val != 0xaffe); } //Read two sync bytes lo = port.ReadByteSerial(); hi = port.ReadByteSerial(); val = ((hi << 8) | lo); Debug.Assert(val == 0xaffe); n++; } } } }

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  • receive string with chars

    - by Meloun
    Hi all, i am quite new in python. I am receiving (through pyserial) string with data values. How can I parse these data to particular data structure? I know that 0-1 byte : id 2-5 byte : time1 =>but little endian (lsb first) 6-9 byte : time2 =>but little endian (lsb first) and I looking for a function: def parse_data(string): data={} data['id'] = ?? data['time1'] = ?? data['time2'] = ?? return data thanks

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  • WPF: Convert memory stream to BitmapImage?

    - by David Veeneman
    I have an image that was originally a PNG that I have converted to a byte[] and saved in a database. Originally, I simply read the PNG into a memory stream and converted the stream into a byte[]. Now I want to read the byte[] back and convert it to a BitmapImage, so that I can bind a WPF Image control to it. I am seeing a lot of contradictory and confusing code online to accomplish the task of converting a byte[] to a BitmapImage. I am not sure whether I need to add any code due to the fact that the image was originally a PNG. Can anyone provide the code to convert the stream to a BitmapImage? Thanks for your help.

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