Unclear debugger break due to ListBox

Question

Hi, 

Please help me with a tool generated debugger. I experienced the same debugger break occasionally due to ListBox operation, but I don't know exactly what the problem is, since it occurs without a clear reason. 

I copy and paste partial code below, 

the debugger always breaks at "if (Debugger.IsAttached) Debugger.Break();". Second line from the last.

    public partial class App : Windows.UI.Xaml.Application
    {
        private Windows.UI.Xaml.Style ListBoxStyle;
        private bool _contentLoaded;

        [System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.Windows.UI.Xaml.Build.Tasks"," 4.0.0.0")]
        [System.Diagnostics.DebuggerNonUserCodeAttribute()]
        public void InitializeComponent()
        {
            if (_contentLoaded)
                return;

            _contentLoaded = true;
#if DEBUG && !DISABLE_XAML_GENERATED_BREAK_ON_UNHANDLED_EXCEPTION
            UnhandledException += (sender, e) =>
            {
                if (Debugger.IsAttached) Debugger.Break();
            };
#endif
        }
    }
}

Thanks in advance!

Jerry

Hi Min, 

Is there a better debugging way to trace backward to the source of error? because I had implement ListBox call in many places throughout the code, it will a daunting work to catch all exceptions individually.

Thank you,

Jerry

Answer 1

Hi Jerry,

When the code breaks, you can try checking e.Exception for more information about this exception.

Best regards,

---

Min Zhu [MSFT]
MSDN Community Support | Feedback to us

Answer 2

Hi Jerry,

From your description this is very likely to be a xaml parsing exception, which would crash the application. So I don't think you can log all the exceptions somehow. This have to be done individually.

Best regards,

---

Min Zhu [MSFT]
MSDN Community Support | Feedback to us

Answer 3

ok, thanks you.

---

Jerry

Answer 4

I was having a similar break with a TextBox.  Whenever the textbox took focus either by clicking it or by tabbing into it, I'd get the break.  I even deleted the control and re-added it back into the app with no change.

The e.Exception info showed

-  Exception {"Specified cast is not valid."} System.Exception {System.InvalidCastException}

but didn't give any pointers to the line or method that caused the exception.  The sender is my app name.  I THINK it's a problem with my click event handlers (I have some paths to enable hot spots on an image and set click events on those paths), but don't know for certain.  I'm going to insert a bunch of Try/Catch blocks into the code to see if I can narrow it down.

Brian

Answer 5

I have the same problem，when i use GridView. I change from GridView A to GridView B, it crashs accidentally, the exception shows "Error HRESULT E_FAIL has been returned from a call to a COM component",but i get nothing in e.message. I think this is a xaml problem, but i can not point out where the problem is,since there is no message.

Answer 6

Same here with VS2012 RC. The culprit was an incorrect markup in a GridView, specifically an incorrect CRLF inserted in a DataTemplate section.

Instead of

Width="Auto"

when cutting and pasting, a

Width="

Auto"

was inserted (note the line break). You must carefully inspect your XAML, looking for illegal characters, etc. Since is a Win32 exception, you cannot inspect it as usual, so if you hit "Continue", a dialog box is opened, prompting you to choose a native code debugger.