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  • Cant insert a object into a silverlight databound combo box

    - by Steve
    Hi Until recently I had a combo box that was bound to a Linq queried IEnumerable of a DataService.Obj type in the bind method, and all worked fine private IEnumerable<DataService.Obj> _GeneralList; private IEnumerable<DataService.Obj> _QueriedList; private void Bind() { _GeneralList = SharedLists.GeneralList; _QueriedList = _GeneralList.Where(q =>q.ID >1000); cmbobox.ItemsSource = _QueriedList; } Then I had to change the method to insert a new obj and set that object as the default obj and now I get a "System.NullReferenceException: Object reference not set to an instance of an object" exception. I know this has to do with inserting into a linq queried ienumerable but I cant fix it. Any help will be gratefully received. private IEnumerable<DataService.Obj> _GeneralList; private IEnumerable<DataService.Obj> _QueriedList; private void Bind() { _GeneralList = SharedLists.GeneralList; _QueriedList = _GeneralList.Where(q =>q.ID >1000); cmbobox.ItemsSource = _QueriedList; DataService.Obj info = new DataService.Obj(); info.ID = "0"; (cmbobox.ItemsSource as ObservableCollection<DataService.Obj>).Insert(0,info); cmbobox.SelectedIndex = 0; } Thanks in advance

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  • How can I use CssResources in UiBinder a generated Cell?

    - by confile
    I want to generate a Cell for a CellWidget with the UiBinder (UiRenderer). What I did to generate the cell is in MyCell.java: public class MyCell implements AbstractCell<MyDto> { public interface Resources extends ClientBundle { @Source({Css.DEFAULT_CSS }) Css css(); } public interface Css extends CssResource { String DEFAULT_CSS = "test/MyStyle.css"; String test(); } interface MyUiRenderer extends UiRenderer { void render(SafeHtmlBuilder sb, String name, SafeStyles styles); } private static MyUiRenderer renderer = GWT.create(MyUiRenderer.class); Resources resources = GWT.create(Resources.class); @Override public void render(SafeHtmlBuilder safeHtmlBuilder, MyDto model) { SafeStyles style = SafeStylesUtils.fromTrustedString(resources.css().test().toString()); renderer.render(safeHtmlBuilder, model.getName(), style); } } My MyCell.ui.xml file looks like this: <!DOCTYPE ui:UiBinder SYSTEM "http://dl.google.com/gwt/DTD/xhtml.ent"> <ui:UiBinder xmlns:ui='urn:ui:com.google.gwt.uibinder'> <ui:with field="name" type="java.lang.String" /> <ui:with field='styles' type='com.google.gwt.safecss.shared.SafeStyles'/> <div style="{styles}"><ui:text from="{name}" /></div> </ui:UiBinder> MyStyle.css: .test { background-color: red; font-size: 20px; display: flex; ... } When I run my code I get the following error: [DEBUG] [mobile] - Rebinding test.client.app.MyCell.MyUiRenderer [DEBUG] [mobile] - Invoking generator com.google.gwt.uibinder.rebind.UiBinderGenerator [ERROR] [mobile] - java.lang.String required, but {styles} returns com.google.gwt.safecss.shared.SafeStyles: <div style='{styles}'> (:9) [ERROR] [mobile] - Deferred binding failed for 'test.client.app.MyCell.MyUiRenderer'; expect subsequent failures [ERROR] [mobile] - (GWT.java:72) 2014-06-08 17:15:05,214 [FATAL] Uncaught Exception: Then I tried to this: in my UiBinder but it does not work. How can I use css style from a CssResource in my UiRenderer?

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  • WPF Event Handler in Another Class

    - by Nathan Tornquist
    I have built a series of event handlers for some custom WPF controls. The event handles format the text displayed when the user enters or leaves a textbox based on the type of data contained (Phone number, zip code, monetary value, etc.) Right now I have all of the events locally in the C# code directly attached to the xaml. Because I have developed a could controls, this means that the logic is repeated a lot, and if I want to change the program-wide functionality I would have to make changes everywhere the event code is located. I am sure there is a way to put all of my event handlers in a single class. Can anyone help point me in the correct direction? I saw this article: Event Handler located in different class than MainWindow But I'm not sure if it directly relates to what I'm doing. I would rather make small changes to the existing logic that I have, as it works, then rewrite everything into commands. I would essentially like to something like this if possible: LostFocus="ExpandedTextBoxEvents.TextBox_LostFocus" It is easy enough to do something like this: private void TextBoxCurrencyGotFocus(object sender, RoutedEventArgs e) { ExpandedTextBoxEvents.TextBoxCurrencyGotFocus(sender, e); } private void TextBoxCurrencyLostFocus(object sender, RoutedEventArgs e) { ExpandedTextBoxEvents.TextBoxCurrencyLostFocus(sender, e); } But that is less elegant.

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  • iOS: display modal view over the top of a UIWebView

    - by Sly
    Is it possible to display a modal view over the top of a UIWebView? I have a UIViewController that loads a WebView. I then want to push a Modal View Controller over the top so that a modal view covers up the WebView temporarily... The WebView is working fine; here's how it's loaded in the View Controller: - (void)loadView { // Initialize webview and add as a subview to LandscapeController's view myWebView = [[[UIWebView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]] autorelease]; myWebView.scalesPageToFit = YES; myWebView.autoresizesSubviews = YES; myWebView.autoresizingMask = (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight); myWebView.delegate = self; self.view = myWebView; } If I attempt to load a Modal View controller from within viewDidLoad, however, no modal view appears: - (void)viewDidLoad { [super viewDidLoad]; // Edit dcftable.html with updated figures NSMutableString *updated_html = [self _updateHTML:@"dcftable"]; // Load altered HTML file as an NSURL request [self.myWebView loadHTMLString:updated_html baseURL:nil]; // If user hasn't paid for dcftable, then invoke the covering modal view if (some_condition) { LandscapeCoverController *landscapeCoverController = [[[LandscapeCoverController alloc] init] autorelease ]; [self presentModalViewController:landscapeCoverController animated:YES]; } } I suspect that there's something that needs to be done with the UIWebView delegate to get it to receive the new modal view...but can't find any discussion or examples of this anywhere...again, the objective is to invoke a modal view that covers over the top of the WebView. Thanks for any thoughts in advance!

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  • Cast exception being generated when using the same type of object

    - by David Tunnell
    I was previously using static variables to hold variable data that I want to save between postbacks. I was having problems and found that the data in these variables is lost when the appdomain ends. So I did some research and decided to go with ViewStates: static Dictionary<string, linkButtonObject> linkButtonDictonary; protected void Page_Load(object sender, EventArgs e) { if (ViewState["linkButtonDictonary"] != null) { linkButtonDictonary = (Dictionary<string, linkButtonObject>)ViewState["linkButtonDictonary"]; } else { linkButtonDictonary = new Dictionary<string, linkButtonObject>(); } } And here is the very simple class I use: [Serializable] public class linkButtonObject { public string storyNumber { get; set; } public string TaskName { get; set; } } I am adding to linkButtonDictionary as a gridview is databound: protected void hoursReportGridView_OnRowDataBound(Object sender, GridViewRowEventArgs e) { if (e.Row.RowType == DataControlRowType.DataRow) { LinkButton btn = (LinkButton)e.Row.FindControl("taskLinkButton"); linkButtonObject currentRow = new linkButtonObject(); currentRow.storyNumber = e.Row.Cells[3].Text; currentRow.TaskName = e.Row.Cells[5].Text; linkButtonDictonary.Add(btn.UniqueID, currentRow); } } It appears that my previous issues are resolved however a new one has arisin. Sometime when I postback I am getting this error: [A]System.Collections.Generic.Dictionary2[System.String,linkButtonObject] cannot be cast to [B]System.Collections.Generic.Dictionary2[System.String,linkButtonObject]. Type A originates from 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' in the context 'LoadNeither' at location 'C:\Windows\Microsoft.Net\assembly\GAC_32\mscorlib\v4.0_4.0.0.0__b77a5c561934e089\mscorlib.dll'. Type B originates from 'mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' in the context 'LoadNeither' at location 'C:\Windows\Microsoft.Net\assembly\GAC_32\mscorlib\v4.0_4.0.0.0__b77a5c561934e089\mscorlib.dll'. I don't understand how there can be a casting issue when I am using the same class everywhere. What am I doing wrong and how do I fix it?

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  • Best way to implement game loop without freezing UI thread

    - by Matt H
    I'm trying to make a simple 2D game in Java. So far I have a JFrame, with a menubar, and a class which extends JPanel and overrides it's paint method. Now, I need to get a game loop going, where I will update the position of images and so on. However, I'm stuck at how best to achieve this. Should I use multi-threading, because surely, if you put an infinite loop on the main thread, the UI (and thus my menu bar) will freeze up? Here's my code so far: import java.awt.Color; import java.awt.Graphics; import javax.swing.JPanel; @SuppressWarnings("serial") public class GameCanvas extends JPanel { public void paint(Graphics g) { while (true) { g.setColor(Color.DARK_GRAY); try { Thread.sleep(100); } catch (InterruptedException e) { e.printStackTrace(); } } } } import javax.swing.JFrame; import javax.swing.JMenu; import javax.swing.JMenuBar; import javax.swing.JMenuItem; @SuppressWarnings("serial") public class Main extends JFrame { GameCanvas canvas = new GameCanvas(); final int FRAME_HEIGHT = 400; final int FRAME_WIDTH = 400; public static void main(String args[]) { new Main(); } public Main() { super("Game"); JMenuBar menuBar = new JMenuBar(); JMenu fileMenu = new JMenu("File"); JMenuItem startMenuItem = new JMenuItem("Pause"); menuBar.add(fileMenu); fileMenu.add(startMenuItem); super.add(canvas); super.setVisible(true); super.setSize(FRAME_WIDTH, FRAME_WIDTH); super.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); super.setJMenuBar(menuBar); } } Any pointers/tips? Also, where should I put my loop? In my main class, or my GameCanvas class? Any help is appreciated, thanks.

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  • Creating a new object destroys an older object with different name in C++

    - by Mikael
    First question here! So, I am having some problems with pointers in Visual C++ 2008. I'm writing a program which will control six cameras and do some processing on them so to clean things up I have created a Camera Manager class. This class handles all operations which will be carried out on all the cameras. Below this is a Camera class which interacts with each individual camera driver and does some basic image processing. Now, the idea is that when the manager is initialised it creates two cameras and adds them to a vector so that I can access them later. The catch here is that when I create the second camera (camera2) the first camera's destructor is called for some reason, which then disconnects the camera. Normally I'd assume that the problem is somewhere in the Camera class, but in this case everything works perfectly as long as I don't create the camera2 object. What's gone wrong? CameraManager.h: #include "stdafx.h" #include <vector> #include "Camera.h" class CameraManager{ std::vector<Camera> cameras; public: CameraManager(); ~CameraManager(); void CaptureAll(); void ShowAll(); }; CameraManager.cpp: #include "stdafx.h" #include "CameraManager.h" CameraManager::CameraManager() { printf("Camera Manager: Initializing\n"); [...] Camera *camera1 = new Camera(NodeInfo,1, -44,0,0); cameras.push_back(*camera1); // Adding the following two lines causes camera1's destructor to be called. Why? Camera *camera2 = new Camera(NodeInfo,0, 44,0,0); cameras.push_back(*camera2); printf("Camera Manager: Ready\n"); }

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  • get and set for class in model - MVC 2 asp.net

    - by bergin
    Hi there, I want to improve the program so it has a proper constructor but also works with the models environment of MVC. I currently have: public void recordDocument(int order_id, string filename, string physical_path, string slug, int bytes) { ArchiveDocument doc = new ArchiveDocument(); doc.order_id = order_id; doc.filename = filename; doc.physical_path = physical_path; doc.slug = slug; doc.bytes = bytes; db.ArchiveDocuments.InsertOnSubmit(doc); } This obviously should be a constructor and should change to the leaner: public void recordDocument(ArchiveDocument doc) { db.ArchiveDocuments.InsertOnSubmit(doc); } with a get & set somewhere else - not sure of the syntax - do I create a partial class? so: creating in the somewhere repository - ArchiveDocument doc = new ArchiveDocument(order_id, idTaggedFilename, physical_path, slug, bytes); and then: namespace ordering.Models { public partial class ArchiveDocument { int order_id, string filename, string physical_path, string slug, int bytes; public archiveDocument(int order_id, string filename, string physical_path, string slug, int bytes){ this.order_id = order_id; etc } } How should I alter the code?

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  • Servlet that starts a thread only once for every visitor

    - by user858749
    Hey I want to implement a Java Servlet that starts a thread only once for every single user. Even on refresh it should not start again. My last approach brought me some trouble so no code^^. Any Suggestions for the layout of the servlet? public class LoaderServlet extends HttpServlet { // The thread to load the needed information private LoaderThread loader; // The last.fm account private String lfmaccount; public LoaderServlet() { super(); lfmaccount = ""; } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { if (loader != null) { response.setContentType("text/plain"); response.setHeader("Cache-Control", "no-cache"); PrintWriter out = response.getWriter(); out.write(loader.getStatus()); out.flush(); out.close(); } else { loader = new LoaderThread(lfmaccount); loader.start(); request.getRequestDispatcher("WEB-INF/pages/loader.jsp").forward( request, response); } } @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { if (lfmaccount.isEmpty()) { lfmaccount = request.getSession().getAttribute("lfmUser") .toString(); } request.getRequestDispatcher("WEB-INF/pages/loader.jsp").forward( request, response); } } The jsp uses ajax to regularly post to the servlet and get the status. The thread just runs like 3 minutes, crawling some last.fm data.

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  • [Netbeans 6.9] Java MethodOverloading error with double values

    - by Nimitips
    Here is a part of my code I'm having trouble with: ===Class Overload=== public class Overload { public void testOverLoadeds() { System.out.printf("Square of integer 7 is %d\n",square(7)); System.out.printf("Square of double 7.5 is %d\n",square(7.5)); }//..end testOverloadeds public int square(int intValue) { System.out. printf("\nCalled square with int argument: %d\n",intValue); return intValue * intValue; }//..end square int public double square(double doubleValue) { System.out.printf("\nCalled square with double argument: %d\n", doubleValue); return doubleValue * doubleValue; }//..end square double }//..end class overload ===Main=== public static void main(String[] args) { Overload methodOverload = new Overload(); methodOverload.testOverLoadeds(); } It compiles with no error, however when I try to run it the output is: Called square with int argument: 7 Square of integer 7 is 49 Exception in thread "main" java.util.IllegalFormatConversionException: d != java.lang.Double at java.util.Formatter$FormatSpecifier.failConversion(Formatter.java:3999) at java.util.Formatter$FormatSpecifier.printInteger(Formatter.java:2709) at java.util.Formatter$FormatSpecifier.print(Formatter.java:2661) at java.util.Formatter.format(Formatter.java:2433) at java.io.PrintStream.format(PrintStream.java:920) at java.io.PrintStream.printf(PrintStream.java:821) at methodoverload.Overload.square(Overload.java:19) at methodoverload.Overload.testOverLoadeds(Overload.java:8) at methodoverload.Main.main(Main.java:9) Called square with double argument:Java Result: 1 What am I doing wrong? I'm on Ubuntu 10.10, Netbeans 6.9. Thanks.

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  • How to play simultaneous multiply audio sources in Silverlight

    - by Shurup
    I want to play simultaneous multiply audio sources in Silverlight. So I've created a prototype in Silverlight 4 that should play a two mp3 files containing the same ticks sound with an intervall 1 second. So these files must be sounded as one sound if they will be played together with any whole second offsets (0 and 1, 0 and 2, 1 and 1 seconds, etc.) I my prototype I use two MediaElement (me and me2) objects. DateTime startTime; private void Play_Clicked(object sender, RoutedEventArgs e) { me.SetSource(new FileStream(file1), FileMode.Open))); me2.SetSource(new FileStream(file2), FileMode.Open))); var timer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(1) }; timer.Tick += RefreshData; timer.Start(); } First file should be played at 00:00 sec. and the second in 00:02 second. void RefreshData(object sender, EventArgs e) { if(me.CurrentState != MediaElementState.Playing) { startTime = DateTime.Now; me.Play(); return; } var elapsed = DateTime.Now - startTime; if(me2.CurrentState != MediaElementState.Playing && elapsed >= TimeSpan.FromSeconds(2)) { me2.Play(); ((DispatcherTimer)sender).Stop(); } } The tracks played every time different and not simultaneous as they should (as one sound).

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  • Flash CS4 Actionscript 3.0 --- Make my script loop!

    - by Ross
    Here is my script... all I want to do is have it continuously loop! import fl.transitions.Tween; import fl.transitions.easing.*; yourwebsite_mc.visible=false; var uptodateFadeTween=new Tween(uptodate_mc,"alpha",Strong.easeOut,0,1,3,true); var uptodateRotateTween=new Tween(uptodate_mc,"rotation",Strong.easeOut,360,0,3,true); var uptodateXTween:Tween=new Tween(uptodate_mc,"x",Strong.easeOut,-250,200,3,true); var uptodateDone:Timer=new Timer(3000,1); uptodateDone.addEventListener(TimerEvent.TIMER, timerDoneF); uptodateDone.start(); function timerDoneF(e:TimerEvent):void { var uptodateYTween:Tween=new Tween(uptodate_mc,"y",Strong.easeOut,129,-150,3,true); } var uptodateFlyUp:Timer=new Timer(3500,1); uptodateFlyUp.addEventListener(TimerEvent.TIMER, timerDoneG); uptodateFlyUp.start(); function timerDoneG(e:TimerEvent):void { yourwebsite_mc.visible=true; var yourwebsiteXTween:Tween=new Tween(yourwebsite_mc,"x",Strong.easeOut,-200,450,1.5,true); }

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  • How to make a program not show up in Alt-Tab or on the taskbar.

    - by Scott Chamberlain
    I have a program that needs to sit in the background and when a user connects to a RDP session it will do some stuff then launch a program. when the program is closed it will do some housekeeping and logoff the session. The current way I am doing it is like this I have the terminal server launch this application. I have it set as a windows forms application and my code is this public static void Main() { //Do some setup work Process proc = new Process(); //setup the process proc.Start(); proc.WaitForExit(); //Do some housecleaning NativeMethods.ExitWindowsEx(0, 0); } I really like this because there is no item in the taskbar and there is nothing showing up in alt-tab. However to do this I gave up access to functions like void WndProc(ref Message m) So Now I can't listen to windows messages (Like WTS_REMOTE_DISCONNECT or WTS_SESSION_LOGOFF) and do not have a handle to use for for bool WTSRegisterSessionNotification(IntPtr hWnd, int dwFlags); I would like my code to be more robust so it will do the housecleaning if the user logs off or disconnects from the session before he closes the program. Any reccomendations on how I can have my cake and eat it too?

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  • Should I use early returns in C#?

    - by Bobby
    I've learned Visual Basic and was always taught to keep the flow of the program without interruptions, like Goto, Exit and Return. Using nested ifs instead of one return statement seems very natural to me. Now that I'm partly migrating towards C#, I wonder what the best practice is for C-like languages. I've been working on a C# project for some time, and of course discover more code of ExampleB and it's hurting my mind somehow. But what is the best practice for this, what is more often used and are there any reasons against one of the styles? public void ExampleA() { if (a != b) { if (a != c) { bool foundIt; for (int i = 0; i < d.Count && !foundIt; i++) { if (element == f) foundIt = true; } } } } public void ExampleB() { if (a == b) return; if (a == c) return; foreach (object element in d) { if (element == f) break; } }

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  • Array passing between classes, gone?

    - by Kenneth
    Hey guys . i have two classes, SelectionScreenTable & GraphView. In the SelectionScreenTable class .h, i declared a NSMutableArray called usagedatas NSMutableArray *usagedatas; } @property (nonatomic, retain) NSMutableArray *usagedatas; In the SelectionScreenTable class.m i remembered to @synthesize. Later on, while processing my methods, i did a NSLog(@"usagedatas count:%i",usagedatas.count); to check whether it has value and it returned 1. so yeah its good up to this point. And in the -(void) dealloc , i remembered to released it . [usagedatas release]; So now comes ME trying to use it in another class. In GraphView.m i imported the "SelectionScreenTable.h". in the -(void)viewDidLoad i did SelectionScreenTable *UD = [SelectionScreenTable alloc]; NSLog(@"GraphView UD.usagedataas.count = :%i",UD.usagedatas.count); it returned 0. Any idea guys?

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  • optimize output value using a class and public member

    - by wiso
    Suppose you have a function, and you call it a lot of times, every time the function return a big object. I've optimized the problem using a functor that return void, and store the returning value in a public member: #include <vector> const int N = 100; std::vector<double> fun(const std::vector<double> & v, const int n) { std::vector<double> output = v; output[n] *= output[n]; return output; } class F { public: F() : output(N) {}; std::vector<double> output; void operator()(const std::vector<double> & v, const int n) { output = v; output[n] *= n; } }; int main() { std::vector<double> start(N,10.); std::vector<double> end(N); double a; // first solution for (unsigned long int i = 0; i != 10000000; ++i) a = fun(start, 2)[3]; // second solution F f; for (unsigned long int i = 0; i != 10000000; ++i) { f(start, 2); a = f.output[3]; } } Yes, I can use inline or optimize in an other way this problem, but here I want to stress on this problem: with the functor I declare and construct the output variable output only one time, using the function I do that every time it is called. The second solution is two time faster than the first with g++ -O1 or g++ -O2. What do you think about it, is it an ugly optimization?

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  • read files from directory and filter files from Java

    - by Adnan
    The following codes goes through all directories and sub-directories and outputs just .java files; import java.io.File; public class DirectoryReader { private static String extension = "none"; private static String fileName; public static void main(String[] args ){ String dir = "C:/tmp"; File aFile = new File(dir); ReadDirectory(aFile); } private static void ReadDirectory(File aFile) { File[] listOfFiles = aFile.listFiles(); if (aFile.isDirectory()) { listOfFiles = aFile.listFiles(); if(listOfFiles!=null) { for(int i=0; i < listOfFiles.length; i++ ) { if (listOfFiles[i].isFile()) { fileName = listOfFiles[i].toString(); int dotPos = fileName.lastIndexOf("."); if (dotPos > 0) { extension = fileName.substring(dotPos); } if (extension.equals(".java")) { System.out.println("FILE:" + listOfFiles[i] ); } } if(listOfFiles[i].isDirectory()) { ReadDirectory(listOfFiles[i]); } } } } } } Is this efficient? What could be done to increase the speed? All ideas are welcome.

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  • Java constructor using generic types

    - by Beer Me
    I'm having a hard time wrapping my head around Java generic types. Here's a simple piece of code that in my mind should work, but I'm obviously doing something wrong. Eclipse reports this error in BreweryList.java: The method breweryMethod() is undefined for the type <T> The idea is to fill a Vector with instances of objects that are a subclass of the Brewery class, so the invocation would be something like: BreweryList breweryList = new BreweryList(BrewerySubClass.class, list); BreweryList.java package com.beerme.test; import java.util.Vector; public class BreweryList<T extends Brewery> extends Vector<T> { public BreweryList(Class<T> c, Object[] j) { super(); for (int i = 0; i < j.length; i++) { T item = c.newInstance(); // breweryMethod() is an instance method // of Brewery, of which <T> is a subclass (right?) c.breweryMethod(); // "The method breweryMethod() is undefined // for the type <T>" } } } Brewery.java package com.beerme.test; public class Brewery { public Brewery() { super(); } protected void breweryMethod() { } } BrewerySubClass.java package com.beerme.test; public class BrewerySubClass extends Brewery { public BrewerySubClass() { super(); } public void brewerySubClassMethod() { } } I'm sure this is a complete-generics-noob question, but I'm stuck. Thanks for any tips!

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  • Strange compilation error on reference passing argument to function

    - by Grewdrewgoo Goobergabbsoen
    Here's the code: #include <iostream> using namespace std; void mysize(int &size, int size2); int main() { int *p; int val; p = &val; cout << p; mysize(&val, 20); // Error is pointed here! } void mysize(int &size, int size2) { cout << sizeof(size); size2 = size2 + 6000; cout << size2; } Here's the error output from GCC: In function 'int main()': Line 10: error: invalid initialization of non-const reference of type 'int&' from a temporary of type 'int*' compilation terminated due to -Wfatal-errors. What does that imply? I do not understand the error message ... invalid initialization of a non-constant? I declared the prototype function above with two parameters to take, one a reference of an integer and one just an integer value itself. I passed the reference of the int (see line 10), yet this error keeps being thrown at me. What is the issue?

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  • eclipse error with android: id cannot be resolved or is not a field

    - by Jaynathan Leung
    Hi, I just started playing around with android development, and already with just an attempt at making a button, I have encountered a problem. The error I'm given in the following code is right on "R.id.button1". It says id cannot be resolved or is not a field. Do I need to manually reference every single object I make in the layout xml file? I found that this did work, but it does seem to be a bit much for every button I want to make... package com.example.helloandroid; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class HelloAndroid extends Activity { /** Called when the activity is first created. */ private Button button1; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); button1 = (Button)findViewById(R.id.button1); button1.setOnClickListener(new OnClickListener() { public void onClick(View v) { finish(); } }); } }

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  • Java: Tracking a user login session - Session EJBs vs HTTPSession

    - by bguiz
    If I want to keep track of a conversational state with each client using my web application, which is the better alternative - a Session Bean or a HTTP Session - to use? Using HTTP Session: //request is a variable of the class javax.servlet.http.HttpServletRequest //UserState is a POJO HttpSession session = request.getSession(true); UserState state = (UserState)(session.getAttribute("UserState")); if (state == null) { //create default value .. } String uid = state.getUID(); //now do things with the user id Using Session EJB: In the implementation of ServletContextListener registered as a Web Application Listener in WEB-INF/web.xml: //UserState NOT a POJO this this time, it is //the interface of the UserStateBean Stateful Session EJB @EJB private UserState userStateBean; public void contextInitialized(ServletContextEvent sce) { ServletContext servletContext = sce.getServletContext(); servletContext.setAttribute("UserState", userStateBean); ... In a JSP: public void jspInit() { UserState state = (UserState)(getServletContext().getAttribute("UserState")); ... } Elsewhere in the body of the same JSP: String uid = state.getUID(); //now do things with the user id It seems to me that the they are almost the same, with the main difference being that the UserState instance is being transported in the HttpRequest.HttpSession in the former, and in a ServletContext in the case of the latter. Which of the two methods is more robust, and why?

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  • Strange results about C++11 memory model (Relaxed ordering)

    - by Dancing_bunny
    I was testing the example in the memory model of the Anthony Williams's book "C++ Concurrency" #include<atomic> #include<thread> #include<cassert> std::atomic_bool x,y; std::atomic_int z; void write_x_then_y() { x.store(true, std::memory_order_relaxed); y.store(true, std::memory_order_relaxed); } void read_y_then_x() { while(!y.load(std::memory_order_relaxed)); if(x.load(std::memory_order_relaxed)) { ++z; } } int main() { x = false; y = false; z = 0; std::thread a(write_x_then_y); std::thread b(read_y_then_x); a.join(); b.join(); assert(z.load()!=0); } According to the explanation, relaxed operations on difference variables (here x and y) can be freely reordered. However, I repeated running the problem for more than several days. I never hit the situation that the assertion (assert(z.load()!=0);) fires. I just use the default optimization and compile the code using g++ -std=c++11 -lpthread dataRaceAtomic.cpp Does anyone actually try it and hit the assertion? Could anyone give me an explanation about my test results? BTW, I also tried the version without using the atomic type, I got the same result. Currently, both programs are running healthily. Thanks.

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  • Simple POSIX threads question

    - by Andy
    Hi, I have this POSIX thread: void subthread(void) { while(!quit_thread) { // do something ... // don't waste cpu cycles if(!quit_thread) usleep(500); } // free resources ... // tell main thread we're done quit_thread = FALSE; } Now I want to terminate subthread() from my main thread. I've tried the following: quit_thread = TRUE; // wait until subthread() has cleaned its resources while(quit_thread); But it does not work! The while() clause does never exit although my subthread clearly sets quit_thread to FALSE after having freed its resources! If I modify my shutdown code like this: quit_thread = TRUE; // wait until subthread() has cleaned its resources while(quit_thread) usleep(10); Then everything is working fine! Could someone explain to me why the first solution does not work and why the version with usleep(10) suddenly works? I know that this is not a pretty solution. I could use semaphores/signals for this but I'd like to learn something about multithreading, so I'd like to know why my first solution doesn't work. Thanks!

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  • EF in a UserControl can't see the app.config?

    - by Sven
    I just created a user control. This control also makes use of my static Entity Framework class to load two comboboxes. All is well and runs without a problem. Design and runtime are working. Then when I stop the application all the forms that contain my UserControl don't work any more in design time. I just see two errors: Error1: The specified named connection is either not found in the configuration, not intended to be used with the EntityClient provider, or not valid. Error 2: The variable ccArtikelVelden is either undeclared or was never assigned. (ccArtikelVelde is my UserControl) Runtime everything is still working My static EF Repositoy class: public class BSManagerData { private static BSManagerEntities _entities; public static BSManagerEntities Entities { get { if (_entities == null) _entities = new BSManagerEntities(); return _entities; } set { _entities = value; } } } Some logic happening in my UserControl to load the data in the comboboxes: private void LaadCbx() { cbxCategorie.DataSource = (from c in BSManagerData.Entities.Categories select c).ToList(); cbxCategorie.DisplayMember = "Naam"; cbxCategorie.ValueMember = "Id"; } private void cbxCategorie_SelectedIndexChanged(object sender, EventArgs e) { cbxFabrikant.DataSource = from f in BSManagerData.Entities.Fabrikants where f.Categorie.Id == ((Categorie)cbxCategorie.SelectedItem).Id select f; cbxFabrikant.DisplayMember = "Naam"; cbxFabrikant.ValueMember = "Id"; } The only way to make my forms work again, design time, is to comment out the EF part in the UserControl (see above) and rebuild. It's very strange, everything is in the same assembly, same namespace (for the sake of simplicity). Anyone an idea?

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  • Call event from original thread ??

    - by user311883
    Hi all, Here is my problem, I have a class which have a object who throw an event and in this event I throw a custom event from my class. But unfortunately the original object throw the event from another thread and so my event is also throw on another thread. This cause a exception when my custom event try to access from controls. Here is a code sample to better understand : class MyClass { // Original object private OriginalObject myObject; // My event public delegate void StatsUpdatedDelegate(object sender, StatsArgs args); public event StatsUpdatedDelegate StatsUpdated; public MyClass() { // Original object event myObject.AnEvent += new EventHandler(myObject_AnEvent); } // This event is called on another thread private void myObject_AnEvent(object sender, EventArgs e) { // Throw my custom event here StatsArgs args = new StatsArgs(..........); StatsUpdated(this, args); } } So when on my windows form I call try to update a control from the event StatsUpdated I get a cross thread exception cause it has been called on another thread. What I want to do is throw my custom event on the original class thread, so control can be used within it. Anyone can help me ?

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