VS2010 Just in time debugger doesn't show entire message - visual-studio-2010

Question

I often get the Just-in-time debugger window, and most often no message is shown, but some times I can't see the entire exception, which could be useful.
When I try to run the debugger I always get an error that another debugger is already atached, which leads me nowhere. The window is not resizable and the text can't be copied.
I'm developing in VS 2010 + C# + Silverlight, and it happens when running via VS.
Any insights?

Answer 1

You get "another debugger is already atached" because you are already in debug mode and your browser's process attached to your code.
Firstly,
Handle global exceptions in your App.xaml
Secondly, In your browser open developer inspector. (F12 for most of browser) and watch console.
http://msdn.microsoft.com/en-us/library/system.windows.application.unhandledexception(v=vs.95).aspx?cs-save-lang=1&cs-lang=csharp#code-snippet-3
using System.IO; // FileNotFoundException
using System.Windows; // Application, StartupEventArgs, ApplicationUnhandledExceptionEventArgs
namespace SilverlightApplication
{
public partial class App : Application
{
public App()
{
this.Startup += this.Application_Startup;
this.UnhandledException += this.Application_UnhandledException;
InitializeComponent();
}
private void Application_Startup(object sender, StartupEventArgs e)
{
this.RootVisual = new Page();
}
private void Application_UnhandledException(object sender,
ApplicationUnhandledExceptionEventArgs e)
{
if (e.ExceptionObject is FileNotFoundException)
{
// Inform the user
// Recover from the error
e.Handled = true;
return;
}
// Exception is unrecoverable so stop the application and allow the
// Silverlight plug-in control to detect and process the exception.
}
}
}
Secondly, In your browser open developer inspector. (F12 for most of browser) and watch console. The message comes from index.aspx which your xap hosted. There is a silverlighterror js function response it.
function onSilverlightError(sender, args) {
var appSource = "";
if (sender != null && sender != 0) {
appSource = sender.getHost().Source;
}
var errorType = args.ErrorType;
var iErrorCode = args.ErrorCode;
if (errorType == "ImageError" || errorType == "MediaError") {
return;
}
var errMsg = "Unhandled Error in Silverlight Application " + appSource + "\n" ;
errMsg += "Code: "+ iErrorCode + " \n";
errMsg += "Category: " + errorType + " \n";
errMsg += "Message: " + args.ErrorMessage + " \n";
if (errorType == "ParserError") {
errMsg += "File: " + args.xamlFile + " \n";
errMsg += "Line: " + args.lineNumber + " \n";
errMsg += "Position: " + args.charPosition + " \n";
}
else if (errorType == "RuntimeError") {
if (args.lineNumber != 0) {
errMsg += "Line: " + args.lineNumber + " \n";
errMsg += "Position: " + args.charPosition + " \n";
}
errMsg += "MethodName: " + args.methodName + " \n";
}
throw new Error(errMsg);
}
Finally, always ensure that (if exist) in your web project's settings.In Web Section there is a Silverlight Checkbox for debugging. It must be checked for debugging attachment.
One more clue: In VS Ctrl + Alt + E and then select CLR exceptions , when you launch you will get more details about error. But do it where error exactly occurs. Because it sometimes give non-errors,but caught by debugger.
Hope helps!