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• Why does my Android App crash when loading image from gallery the 2nd time?

  - by Sebastian

  Hi folks, I've written an app, thats loading images either using the android gallery app or by taking a photo using the cam. When I now load an image using the gallery, everything is fine. When the code is being executed a second time (for loading another image), the application crashes. try { Uri data = intent.getData(); ContentResolver cr = this.getContentResolver(); Bitmap mBitmap = null; mBitmap = Media.getBitmap(cr, data); imageView.setImageBitmap(mBitmap); } catch(Exception e){ showToast(this, "Failed loading image from gallery"); return; } The code crashes at the line mBimap = Media.getBitmap(cr, data);. Everything is initialized, there are no null values etc. The strange thing is: no exception is thrown, I don't get into the catch block to determine whats going wrong. Does anyone have an idea about this? Am I not allowed to "re-use" the content resolver? Do I have to free it after the first usage or something like this?

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• C++'s std::string pools, debug builds? std::string and valgrind problems

  - by Den.Jekk

  Hello, I have a problem with many valgrind warnings about possible memory leaks in std::string, like this one: 120 bytes in 4 blocks are possibly lost in loss record 4,192 of 4,687 at 0x4A06819: operator new(unsigned long) (vg_replace_malloc.c:230) by 0x383B89B8B0: std::string::_Rep::_S_create(unsigned long, unsigned long, std::allocator<char> const&) (in /usr/lib64/libstdc++.so.6.0.8) by 0x383B89C3B4: (within /usr/lib64/libstdc++.so.6.0.8) by 0x383B89C4A9: std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, unsigned long, std::allocator<char> const&) (in /usr/lib64/libstdc++.so.6.0.8) I'm wondering: does std::string (GCC 4.1.2) use any memory pools? if so, is there any way to disable the pools (in form of a debug build etc.)? Regards, Den

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• Unmanaged Process in Mono

  - by Residuum

  I want to start a quite expensive process (jackd) from a Mono application, and do not need full access to the process from the application itself. As the process is so expensive in terms of CPU usage, a Glib.IdleHandler for polling the process will not work, as it is never executed, and the GUI becomes unresponsive. Is there any way to have the cake and eating it at the same time in Mono? EDIT: I only need to be able to start and stop the process from Mono, I do not need information about the state of the process or if it has exited, as my application will register itself as a client to jackd, basically I need a "replacement" for bash's jackd &>/dev/null 2>&1 & for the System.Diagnostics.Process ;). Here is what I have so far for starting and stopping the process: public void StartJackd() { _jackd = new Process (); _jackd.StartInfo = _jackdStartup; if (_jackd.Start ()) { _jackd.EnableRaisingEvents = true; _jackd.Exited += JackdExited; } } public void StopJackd() { if (_jackd != null && !_jackd.HasExited) { _jackd.CloseMainWindow (); } } And somewhere else I have this code for registering the IdleHandler: GLib.Idle.Add(new GLib.IdleHandler(UpdateJackdConnections)); This handler will fire all the time, while the process is not running, but never, when jackd is running.

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• VS 2008 linking error

  - by AvatarBlue

  I'm using Visual Studio 2008 C++ and working on a dll project. Debug compiled and linked perfectly but when I compile the release version, it shows this: VImgPtr.obj : error LNK2001: unresolved external symbol @__security_check_cookie@4 VLibraryPtr.obj : error LNK2001: unresolved external symbol "void __cdecl operator delete[](void *)" (??_V@YAXPAX@Z) D:\Source Code\VImgLib\Release-vc9u\VImgLib-vc9u.dll : fatal error LNK1120: 2 unresolved externals If I selected Multi-threaded (/MT) in "C/C++-Code Generation tab), it linked ok. The problem is only when I choose Multi-threaded DLL (/MD). I'm releasing a dll, so should be /MD right?

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• Mule ESB 3.2 Splitter destroys Enricher results

  - by Eddie

  Here is the snippet of my flow: <logger message="PRODUCT_ID = #[header:productID]" level="INFO" doc:name="Logger"/> <splitter evaluator="jxpath" expression="//*/BisacHeaderCodes" doc:name="Splitter"/> <logger message="PRODUCT_ID_POST_SPLITTER = #[header:productID]" level="INFO" doc:name="Logger"/> #[header:productID] was set up prior to Logger call. I tried #[variable:productID] and got the same result. When I run it, this is the out put I get: INFO 2012-04-05 23:12:47,865 [[bookinista_order_management].connector.http.mule.default.receiver.02] org.mule.api.processor.LoggerMessageProcessor: PRODUCT_ID = 72 ERROR 2012-04-05 23:12:47,871 [[bookinista_order_management].connector.http.mule.default.receiver.02] org.mule.exception.DefaultSystemExceptionStrategy: Caught exception in Exception Strategy: Expression Evaluator "header" with expression "outbound:productID" returned null but a value was required. org.mule.api.expression.RequiredValueException: Expression Evaluator "header" with expression "outbound:productID" returned null but a value was required. So, right before Splitter, I have a perfect value in my header, and right after Splitter, that value disappears! I understand that Splitter propagates only part of payloda, but shouldn't it leave headers and variables alone? Any ideas for a workaround?

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• CompareValidator works in listview's editItemTemplate but not in insertitemtemplate

  - by Sam

  Hi, I have a validation problem I have a listview, in the edit item template I have two composite controls with a textbox inside I put a comparevalidator on it <asp:CompareValidator ID="myCompareValidator" runat="server" ControlToValidate="mycompositecontrol1" ControlToCompare="mycompositecontrol2" Operator="GreaterThanEqual" Type="Date" Display="Dynamic" ErrorMessage="there is an error !" Text="!" ValidationGroup="myValidationGroup" /> It works great ! so I do exactly the same operation in the InserItemTemplate (It's a copy/paste) but this time, it doesn't work, I have no error message in my validationsummary and near my control to validate! If you know that problem, help me please thanks in advance

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• How to use a string as a delimiter shell script

  - by Dan

  I am reading a line and am using regex to match it in my script. (/bin/bash) echo $line | grep -E '[Ss][Uu][Bb][Jj][Ee][Cc][Tt]: [Hh][Ee][Ll][Pp]' > /dev/null 2>&1 if [[ $? = "0" && -z $subject ]]; then subject=`echo $line | cut -d: -f2` > /dev/null echo "Was able to grab a SUBJECT $line and the actual subject is -> $subject" >> $logfile fi now my problem is that i use the colon as the delimiter. but sometimes the email will have multiple colons in the subject and so I am not able to grab the whole subject because of that. I am looking for a way to grab everything after the colon following subject. even is there is a way to loop through and check for a colon or what. maybe cut allows you to cut with a string as delimiter? Not sure...any ideas? Thanks!

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• How to get at JSON in grails 2.0

  - by Mikey

  I am sending myself JSON like so with jQuery: $.ajax ({ type: "POST", url: 'http://localhost:8080/myproject/myController/myAction', dataType: 'json', async: false, //json object to sent to the authentication url data: {"stuff":"yes", "listThing":[1,2,3], "listObjects":[{"one":"thing"},{"two":"thing2"}]}, success: function () { alert("Thanks!"); } }) I send this to a controller and do println params And I know I'm already in trouble... [stuff:yes, listObjects[1][two]:thing2, listObjects[0][one]:thing, listThing[]:[1, 2, 3], action:myAction, controller:myController] I cannot figure out how to get at most of these values... I can get "yes" with params.stuff, but I cant do params.listThing.each{} or params.listObjects.each{} What am I doing wrong? UPDATE: I make the controller do this to try the two suggestions so far: println params println params.stuff println params.list('listObjects') println params.listThing def thisWontWork = JSON.parse(params.listThing) render("omg l2json") look how weird the parameters look at the end of the null pointer exception when I try the answers: [stuff:yes, listObjects[1][two]:thing2, listObjects[0][one]:thing, listThing[]:[1, 2, 3], action:l2json, controller:rateAPI] yes [] null | Error 2012-03-25 22:16:13,950 ["http-bio-8080"-exec-7] ERROR errors.GrailsExceptionResolver - NullPointerException occurred when processing request: [POST] /myproject/myController/myAction - parameters: stuff: yes listObjects[1][two]: thing2 listObjects[0][one]: thing listThing[]: 1 listThing[]: 2 listThing[]: 3 UPDATE 2 I am learning things, but this can't be right: println params['listThing[]'] println params['listObjects[0][one]'] prints [1, 2, 3] thing It seems like this is some part of grails new JSON marshaling. This is somewhat inconvenient for my purposes of hacking around with the values. How would I get all these individual params back into a big groovy object of nested maps and lists? Maybe I am not doing what I want with jQuery?

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• ASP.NET how can access public properties of MasterPage from external Class ?

  - by eugeneK

  Why i can't access MasterPage's public property (MessagePlaceholder) from other Class (Errors) ? my master page code behind using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; public partial class MyMasterPage : System.Web.UI.MasterPage { public string MessagePlaceholder { get { return messagePlaceholder.InnerHtml; } set { messagePlaceholder.InnerHtml = value; } } protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { messagePlaceholder.InnerHtml = Errors.getMessage(); } } } my Errors Class public static string getMessage() { HttpContext c = HttpContext.Current; string messageType = ""; if (c.Session["errorMessage"] != null) { messageType = "errorMessage"; } else if (c.Session["successMessage"] != null) { messageType = "successMessage"; } if (!string.IsNullOrEmpty(messageType)) { StringBuilder userMessageSb = new StringBuilder(); userMessageSb.Append(string.Format("<div id=\"{0}\" title=\"{1}\">{2}</div>", messageType, messageType.Replace("Message",string.Empty), c.Session[messageType])); // fix so message will not re-appear c.Session.Remove(messageType); messageType = userMessageSb.ToString(); } return messageType; } public static void setSuccess(string successMessage, bool isRedirect) { HttpContext.Current.Session["successMessage"] = successMessage; } public static void setError(string errorMessage, bool isRedirect) { HttpContext.Current.Session["errorMessage"] = errorMessage; if (!isRedirect) { ((HttpContext.Current.CurrentHandler as System.Web.UI.Page).Master as MyMasterPage).MessagePlaceholder = getMessage(); } } this is how i set error if (true) { Errors.setError("this is an error demo", false); return; } or with redirect after error if (true) { Errors.setError("yet another error", true); Response.Redirect("~/error.aspx"); }

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• HASHREF in Perl

  - by Uri

  I'm trying to decrypt a Perl code which I'm not familiar with, somehow related to HashRef. I'm using Amazon::S3, but my question is a general Perl question. See the code below: use Amazon::S3; my $s3 = Amazon::S3-new( ... ); my $response = $s3-buckets; Documentation (here) sais, about s3-buckets: Returns undef on error, else HASHREF of results The following line is working for me, but I don't understand why: for $b in ( @ { $response-{buckets} } ) { print "bucket: " . $b-bucket . "\n"; } I'm buzzled by each operator on the first line. What type exactly are $response, $respone-{bucket}. Looks like the expression within the 'for' is an array, but I don't understand this syntax: @{ ... }?

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• entity framework insert bug

  - by tmfkmoney

  I found a previous question which seemed related but there's no resolution and it's 5 months old so I've opened my own version. http://stackoverflow.com/questions/1545583/entity-framework-inserting-new-entity-via-objectcontext-does-not-use-existing-e When I insert records into my database with the following it works fine for a while and then eventually it starts inserting null values in the referenced field. This typically happens after I do an update on my model from the database although not always after I do an update. I'm using a MySQL database for this. I have debugged the code and the values are being set properly before the save event. They're just not getting inserted properly. I can always fix this issue by re-creating the model without touching any of my code. I have to recreate the entire model, though. I can't just dump the relevant tables and re-add them. This makes me think it doesn't have anything to do with my code but something with the entity framework. Does anyone else have this problem and/or solved it? using (var db = new MyModel()) { var stocks = from record in query let ticker = record.Ticker select new { company = db.Companies.FirstOrDefault(c => c.ticker == ticker), price = Convert.ToDecimal(record.Price), date_stamp = Convert.ToDateTime(record.DateTime) }; foreach (var stock in stocks) { if (stock.company != null) { var price = new StockPrice { Company = stock.company, price = stock.price, date_stamp = stock.date_stamp }; db.AddToStockPrices(price); } } db.SaveChanges(); }

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• What is the simplest way to implement multithreading in c# to existing code

  - by Kaeso

  I have already implemented a functionnal application that parses 26 pages of html all at once to produce an xml file with data contained on the web pages. I would need to implement a thread so that this method can work in the background without causing my app to seems unresponsive. Secondly, I have another function that is decoupled from the first one which compares two xml files to produce a third one and then transform this third xml file to produce an html page using XSLT. This would have to be on a thread, where I can click Cancel to stop the thread whithout crashing the app. What is the easiest best way to do this using WPF forms in VS 2010 ? I have chosen to use the BackgroundWorker. BackgroundWorker implementation: public partial class MainWindow : Window { private BackgroundWorker bw = new BackgroundWorker(); public MainWindow() { InitializeComponent(); bw.WorkerReportsProgress = true; bw.DoWork += new DoWorkEventHandler(bw_DoWork); bw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(backgroundWorker1_RunWorkerCompleted); } private void Window_Loaded(object sender, RoutedEventArgs e) { this.LoadFiles(); } private void btnCompare_Click(object sender, EventArgs e) { if (bw.IsBusy != true) { progressBar2.IsIndeterminate = true; // Start the asynchronous operation. bw.RunWorkerAsync(); } } private void bw_DoWork(object sender, DoWorkEventArgs e) { StatsProcessor proc = new StatsProcessor(); if (lstStatsBox1.SelectedItem != null) if (lstStatsBox2.SelectedItem != null) proc.CompareStats(lstStatsBox1.SelectedItem.ToString(), lstStatsBox2.SelectedItem.ToString()); } private void backgroundWorker1_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e) { progressBar2.IsIndeterminate = false; progressBar2.Value = 100; } I have started with the bgworker solution, but it seems that the bw_DoWork method is never called when btnCompare is clicked, I must be doing something wrong... I am new to threads.

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• CreateThread() fails on 64 bit Windows, works on 32 bit Windows. Why?

  - by Stephen Kellett

  Operating System: Windows XP 64 bit, SP2. I have an unusual problem. I am porting some code from 32 bit to 64 bit. The 32 bit code works just fine. But when I call CreateThread() for the 64 bit version the call fails. I have three places where this fails. 2 call CreateThread(). 1 calls beginthreadex() which calls CreateThread(). All three calls fail with error code 0x3E6, "Invalid access to memory location". The problem is all the input parameters are correct. HANDLE h; DWORD threadID; h = CreateThread(0, // default security 0, // default stack size myThreadFunc, // valid function to call myParam, // my param 0, // no flags, start thread immediately &threadID); All three calls to CreateThread() are made from a DLL I've injected into the target program at the start of the program execution (this is before the program has got to the start of main()/WinMain()). If I call CreateThread() from the target program (same params) via say a menu, it works. Same parameters etc. Bizarre. If I pass NULL instead of &threadID, it still fails. If I pass NULL as myParam, it still fails. I'm not calling CreateThread from inside DllMain(), so that isn't the problem. I'm confused and searching on Google etc hasn't shown any relevant answers. If anyone has seen this before or has any ideas, please let me know. Thanks for reading.

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• How to make a self contained jQuery plugin that finds the tallest image height?

  - by Jannis

  I have been trying to make this to be a little jQuery plugin that I can reuse in the future without having to write the following into my actions.js file in full. This works when loaded in the same file where I set the height using my variable tallest. var tallest = null; $('.slideshow img').each(function(index) { if ($(this).height() >= tallest ) { tallest = $(this).height(); } }); $('.slideshow').height(tallest); This works and will cycle through all the items, then set the value of tallest to the greatest height found. The following however does not work: This would be the plugin, loaded from its own file (before the actions.js file that contains the parts using this): (function($){ $.fn.extend({ tallest: function() { var tallest = null; return this.each(function() { if ($(this).height() >= tallest ) { tallest = $(this).height(); } }); } }); })(jQuery); Once loaded I am trying to use it as follows: $('.slideshow img').tallest(); $('.slideshow').height(tallest); However the above two lines return an error of 'tallest is undefined'. How can I make this work? Any ideas would be appreciated. Thinking about this even more the perfect usage of this would be as follows: $('.container').height(tallest('.container item')); But I wouldn't even know where to begin to get this to work in the manner that you pass the object to be measured into the function by adding it into the brackets of the function name. Thanks for reading, Jannis

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• AutoMapper : Site wide usage of IValueFormatter for given types

  - by CRice

  It is my understanding I can configure AutoMapper in the following way and during mapping it should format all source model dates to the rules defined in the IValueFormatter and set the result to the mapped model. ForSourceType<DateTime>().AddFormatter<StandardDateFormatter>(); ForSourceType<DateTime?>().AddFormatter<StandardDateFormatter>(); I get no effect for my mapped class with this. It only works when I do the following: Mapper.CreateMap<Member, MemberForm>().ForMember(x => x.DateOfBirth, y => y.AddFormatter<StandardDateFormatter>()); I am mapping DateTime? Member.DateOfBirth to string MemberForm.DateOfBirth. The formatter basically creates a short date string from the date. Is there something I am missing when setting the default formatter for a given type? Thanks public class StandardDateFormatter : IValueFormatter { public string FormatValue(ResolutionContext context) { if (context.SourceValue == null) return null; if (!(context.SourceValue is DateTime)) return context.SourceValue.ToNullSafeString(); return ((DateTime)context.SourceValue).ToShortDateString(); } }

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• final transient fields and serialization

  - by doublep

  Is it possible to have final transient fields that are set to any non-default value after serialization in Java? My usecase is a cache variable — that's why it is transient. I also have a habit of making Map fields that won't be changed (i.e. contents of the map is changed, but object itself remains the same) final. However, these attributes seem to be contradictory — while compiler allows such a combination, I cannot have the field set to anything but null after unserialization. I tried the following, without success: simple field initialization (shown in the example): this is what I normally do, but the initialization doesn't seem to happen after unserialization; initialization in constructor (I believe this is semantically the same as above though); assigning the field in readObject() — cannot be done since the field is final. In the example cache is public only for testing. import java.io.*; import java.util.*; public class test { public static void main (String[] args) throws Exception { X x = new X (); System.out.println (x + " " + x.cache); ByteArrayOutputStream buffer = new ByteArrayOutputStream (); new ObjectOutputStream (buffer).writeObject (x); x = (X) new ObjectInputStream (new ByteArrayInputStream (buffer.toByteArray ())).readObject (); System.out.println (x + " " + x.cache); } public static class X implements Serializable { public final transient Map <Object, Object> cache = new HashMap <Object, Object> (); } } Output: test$X@1a46e30 {} test$X@190d11 null

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• Strange behavior with ajax call complete in JavaScript modules

  - by user2598794

  I have 3 simple modules with JavaScript code and JQuery ajax call. First module lots.js: var Lots = (function ($) { var self = this; var processIsRunning; return { getLots: function (lotsUrl) { var items = []; self.processIsRunning = true; var request = $.ajax({ url: lotsUrl, type: 'POST', success: function (data) { //some code } }); $.when(request).done(function() { //some code self.processIsRunning = false; }); }, isComplete: function () { return !self.processIsRunning; } }; }(jQuery)); Module bids.js: var Bids = (function ($) { return { makeBids: function (bidUrl) { //some code } }; }(jQuery)); Module app.js which bundles all together: var App = (function () { var lots_url = null; var bid_url = null; var self = this; return { if (!self.lots_url) { self.lots_url = lotsUrl; } GetLots: function (lotsUrl) { Lots.getLots(self.lots_url); }, MakeBids: function makeBid(bidUrl) { //some code var isComp = Lots.isComplete(); while (!isComp) { isComp = Lots.isComplete(); } Bids.makeBids(self.bid_url); } }; }()); But in the 'while' loop I always get 'isComplete=false'. In debug I see that 'processIsRunning' in Lots module is always true. What's the problem?

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• Inserting into an Associative array?

  - by RedShft

  I'm playing around with associative arrays right now and I can't seem to figure out how to add additional objects to the array. I tried insert but it doesn't recognize both arguments. Also, if I do this it produces an error: Node[bool] test; Node node; Node[bool] temp = [ false:node ]; test ~= temp; //Error 1 Error: cannot append type Node[bool] to type //Node[bool] C:\Users\CP\Documents\Visual Studio //2010\Projects\D\STDS\NPC.d 256 Does this mean you can't use the append operator on associative arrays ?

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• Oracle User definied aggregate function for varray of varchar

  - by baju

  I am trying to write some aggregate function for the varray and I get this error code when I'm trying to use it with data from the DB: ORA-00600 internal error code, arguments: [kodpunp1], [], [], [], [], [], [], [], [], [], [], [] [koxsihread1], [0], [3989], [45778], [], [], [], [], [], [], [], [] Code of the function is really simple(in fact it does nothing ): create or replace TYPE "TEST_VECTOR" as varray(10) of varchar(20) ALTER TYPE "TEST_VECTOR" MODIFY LIMIT 4000 CASCADE create or replace type Test as object( lastVector TEST_VECTOR, STATIC FUNCTION ODCIAggregateInitialize(sctx in out Test) return number, MEMBER FUNCTION ODCIAggregateIterate(self in out Test, value in TEST_VECTOR) return number, MEMBER FUNCTION ODCIAggregateMerge(self IN OUT Test, ctx2 IN Test) return number, MEMBER FUNCTION ODCIAggregateTerminate(self IN Test, returnValue OUT TEST_VECTOR, flags IN number) return number ); create or replace type body Test is STATIC FUNCTION ODCIAggregateInitialize(sctx in out Test) return number is begin sctx := Test(TEST_VECTOR()); return ODCIConst.Success; end; MEMBER FUNCTION ODCIAggregateIterate(self in out Test, value in TEST_VECTOR) return number is begin self.lastVector := value; return ODCIConst.Success; end; MEMBER FUNCTION ODCIAggregateMerge(self IN OUT Test, ctx2 IN Test) return number is begin return ODCIConst.Success; end; MEMBER FUNCTION ODCIAggregateTerminate(self IN Test, returnValue OUT TEST_VECTOR, flags IN number) return number is begin returnValue := self.lastVector; return ODCIConst.Success; end; end; create or replace FUNCTION test_fn (input TEST_VECTOR) RETURN TEST_VECTOR PARALLEL_ENABLE AGGREGATE USING Test; Next I create some test data: create table t1_test_table( t1_id number not null, t1_value TEST_VECTOR not null, Constraint PRIMARY_KEY_1 PRIMARY KEY (t1_id) ) Next step is to put some data to the table insert into t1_test_table (t1_id,t1_value) values (1,TEST_VECTOR('x','y','z')) Now everything is prepared to perform queries: Select test_fn(TEST_VECTOR('y','x')) from dual Query above work well Select test_fn(t1_value) from t1_test_table where t1_id = 1 Version of Oracle DBMS I use: 11.2.0.3.0 Does anyone tried do such a thing? What can be the reason that it does not work? How to solve it? Thanks in advance for help.

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• Multiset of shared_ptrs as a dynamic priority queue: Concept and practice

  - by Sarah

  I was using a vector-based priority queue typedef std::priority_queue< Event, vector< Event >, std::greater< Event > > EventPQ; to manage my Event objects. Now my simulation has to be able to find and delete certain Event objects not at the top of the queue. I'd like to know if my planned work-around can do what I need it to, and if I have the syntax right. I'd also like to know if dramatically better solutions exist. My plan is to make EventPQ a multiset of smart pointers to Event objects: typedef std::multi_set< boost::shared_ptr< Event > > EventPQ; I'm borrowing functions of the Event class from a related post on a multimap priority queue. // Event.h #include <cstdlib> using namespace std; #include <set> #include <boost/shared_ptr.hpp> class Event; typedef std::multi_set< boost::shared_ptr< Event > > EventPQ; class Event { public: Event( double t, int eid, int hid ); ~Event(); void add( EventPQ& q ); void remove(); bool operator < ( const Event & rhs ) const { return ( time < rhs.time ); } bool operator > ( const Event & rhs ) const { return ( time > rhs.time ); } double time; int eventID; int hostID; EventPQ* mq; EventPQ::iterator mIt; }; // Event.cpp Event::Event( double t, int eid, int hid ) { time = t; eventID = eid; hostID = hid; } Event::~Event() {} void Event::add( EventPQ& q ) { mq = &q; mIt = q.insert( boost::shared_ptr<Event>(this) ); } void Event::remove() { mq.erase( mIt ); mq = 0; mIt = EventPQ::iterator(); } I was hoping that by making EventPQ a container of pointers, I could avoid wasting time copying Events into the container and avoid accidentally editing the wrong copy. Would it be dramatically easier to store the Events themselves in EventPQ instead? Does it make more sense to remove the time keys from Event objects and use them instead as keys in a multimap? Assuming the current implementation seems okay, my questions are: Do I need to specify how to sort on the pointers, rather than the objects, or does the multiset automatically know to sort on the objects pointed to? If I have a shared_ptr ptr1 to an Event that also has a pointer in the EventPQ container, how do I find and delete the corresponding pointer in EventPQ? Is it enough to .find( ptr1 ), or do I instead have to find by the key (time)? Is the Event::remove() sufficient for removing the pointer in the EventPQ container? There's a small chance multiple events could be created with the same time (obviously implied in the use of multiset). If the find() works on event times, to avoid accidentally deleting the wrong event, I was planning to throw in a further check on eventID and hostID. Does this seem reasonable? (Dumb syntax question) In Event.h, is the declaration of dummy class Event;, then the EventPQ typedef, and then the real class Event declaration appropriate? I'm obviously an inexperienced programmer with very spotty background--this isn't for homework. Would love suggestions and explanations. Please let me know if any part of this is confusing. Thanks.

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• What is Ruby's double-colon (::) all about?

  - by Meltemi

  I'd probably be able to answer this for myself if "::" wasn't so hard to Google. Didn't see anything on SO so thought I'd try my luck. What is this double-colon :: all about? I see it everywhere in Rails: class User < ActiveRecord::Base or… ActionController::Routing::Routes.draw do |map| I found a definition from this guy: The :: is a unary operator that allows: constants, instance methods and class methods defined within a class or module, to be accessed from anywhere outside the class or module. but that just leads to more questions. What good is scope (private, protected) if you can just use :: to expose anything?

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• my dialog box did not show up whene i compile it using sdk 7.1,

  - by zirek

  hello and welcom everyone .. i'd like to build a win32 application using sdk 7.1, i create the dialog box using visual c++ 2012 resource editor, i copy resource.rc and resource.h to my folder and i write this simple main.cpp file: #include <windowsx.h> #include <Windows.h> #include <tchar.h> #include "resource.h" #define my_PROCESS_MESSAGE(hWnd, message, fn) \ case(message): \ return( \ SetDlgMsgResult(hWnd, uMsg, \ HANDLE_##message((hWnd), (wParam), (lParam), (fn)) )) \ LRESULT CALLBACK DlgProc(HWND, UINT, WPARAM, LPARAM); BOOL Cls_OnInitDialog(HWND hwnd, HWND hwndFocus, LPARAM lParam); void Cls_OnCommand(HWND hwnd, int id, HWND hwndCtl, UINT codeNotify); int WINAPI _tWinMain( HINSTANCE hInstance, HINSTANCE, LPTSTR, int iCmdLine ) { DialogBoxParam( hInstance, MAKEINTRESOURCE(IDD_INJECTOR), NULL, (DLGPROC) DlgProc, NULL ); return FALSE; } LRESULT CALLBACK DlgProc( HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam ) { switch (uMsg) { my_PROCESS_MESSAGE(hwnd, WM_INITDIALOG, Cls_OnInitDialog); my_PROCESS_MESSAGE(hwnd, WM_COMMAND, Cls_OnCommand); default: break; } return DefWindowProc(hwnd, uMsg, wParam, lParam); } BOOL Cls_OnInitDialog(HWND hwnd, HWND hwndFocus, LPARAM lParam) { return TRUE; } void Cls_OnCommand(HWND hwnd, int id, HWND hwndCtl, UINT codeNotify) { switch(id) { case IDCANCEL: EndDialog(hwnd, id); break; default: break; } } then i use the following command line to compile my code, wich i found on this forum cl main.cpp /link /SUBSYSTEM:WINDOWS user32.lib my problem is that my dialog box did not show up, and when i use procexp, to see what happen, i found that that my application is created then closed in the same time, and what make me wondering is that its working fine on visual c++ 2012. my sdk 7.1, installed correctly, i testing it against a basic window without any resource file any ideas, ill be really thankful Best, Zirek

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• Forcing a templated object to construct from a pointer

  - by SalamiArmi

  I have a fictional class: template<typename T> class demonstration { public: demonstration(){} ... T *m_data; } At some point in the program's execution, I want to set m_data to a big block of allocated memory and construct an object T there. At the moment, I've been using this code: void construct() { *m_data = T(); } Which I've now realised is probably not the best idea... wont work under certain cirumstances, if T has a private assignment operator for example. Is there a normal/better way to do what I'm attempting here?

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• Is the C++ compiler optimizer allowed to break my destructor ability to be called multiple times?

  - by sharptooth

  We once had an interview with a very experienced C++ developer who couldn't answer the following question: is it necessary to call the base class destructor from the derived class destructor in C++? Obviously the answer is no, C++ will call the base class destructor automagically anyway. But what if we attempt to do the call? As I see it the result will depend on whether the base class destructor can be called twice without invoking erroneous behavior. For example in this case: class BaseSafe { public: ~BaseSafe() { } private: int data; }; class DerivedSafe { public: ~DerivedSafe() { BaseSafe::~BaseSafe(); } }; everything will be fine - the BaseSafe destructor can be called twice safely and the program will run allright. But in this case: class BaseUnsafe { public: BaseUnsafe() { buffer = new char[100]; } ~BaseUnsafe () { delete[] buffer; } private: char* buffer; }; class DerivedUnsafe { public: ~DerivedUnsafe () { BaseUnsafe::~BaseUnsafe(); } }; the explicic call will run fine, but then the implicit (automagic) call to the destructor will trigger double-delete and undefined behavior. Looks like it is easy to avoid the UB in the second case. Just set buffer to null pointer after delete[]. But will this help? I mean the destructor is expected to only be run once on a fully constructed object, so the optimizer could decide that setting buffer to null pointer makes no sense and eliminate that code exposing the program to double-delete. Is the compiler allowed to do that?

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• Android Camera intent creating two files

  - by Kyle Ramstad

  I am making a program that takes a picture and then shows it's thumbnail. When using the emulator all goes well and the discard button deletes the photo. But on a real device the camera intent saves the image at the imageUri variable and a second one that is named like if I had just opened up the camera and took a picture by itself. private static final int CAMERA_PIC_REQUEST = 1337; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.camera); //start camera values = new ContentValues(); values.put(MediaStore.Images.Media.TITLE, "New Picture"); values.put(MediaStore.Images.Media.DESCRIPTION,"From your Camera"); imageUri = getContentResolver().insert(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values); image = (ImageView) findViewById(R.id.ImageView01); Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); intent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri); startActivityForResult(intent, CAMERA_PIC_REQUEST); //save the image buttons Button save = (Button) findViewById(R.id.Button01); Button close = (Button) findViewById(R.id.Button02); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { if (requestCode == CAMERA_PIC_REQUEST && resultCode == RESULT_OK) { try{ thumbnail = MediaStore.Images.Media.getBitmap(getContentResolver(), imageUri); image.setImageBitmap(thumbnail); } catch(Exception e){ e.printStackTrace(); } } else{ finish(); } } public void myClickHandler(View view) { switch (view.getId()) { case R.id.Button01: finish(); break; case R.id.Button02: dicard(); } } private void dicard(){ getContentResolver().delete(imageUri, null, null); finish(); }

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