Unhandled exception ignored?

[sb]

In the simplified code below, shouldn't the thrown exception cause the app
to terminate since it is unhandled? It doesn't seem to do anything in Debug
or Release mode. I do get a first-chance exception message in the debugger
but that's it. Something seems to be intercepting the exception and
handling it...but I don't know what.

Any info would be appreciated
-sb



// Entire program
using System;
using System.Windows.Forms;

static class Program
{
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
}

public class Form1 : Form
{
public Form1()
{
this.AllowDrop = true;
this.DragDrop += new
System.Windows.Forms.DragEventHandler(this.Form1_DragDrop);
this.DragOver += new
System.Windows.Forms.DragEventHandler(this.Form1_DragOver);
}

private void Form1_DragOver(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Copy; // We'll accept any kind of drop
}

private void Form1_DragDrop(object sender, DragEventArgs e)
{
throw new InvalidOperationException("DragDrop exception."); //
nothing happens here
}
}

 

[Stoitcho Goutsev \(100\)]

DragDrop event called as a result of COM drag and drop operation and is
called directly by COM. If any exception should happen they are probably
re-routed to the caller (which is not your application) and it looks like
they get swallowed.

 

[sb]

Thanks for the reply but what does this have to do with COM? I thought
drag/drop events were just normal windows messages (ie WM_DROPFILES). I'll
have to look into that some more I guess. The wierd part is that if I wrap
the exception in a try/catch block within the Form.DragDrop event, I can
intercept it just like any other exception. I thought another thread might
be handling the exception but the ManagedThreadID within the method is the
same as the rest of the application.

I would like to understand this issue better...I just don't get it

-sb

DragDrop event called as a result of COM drag and drop operation and is
called directly by COM. If any exception should happen they are probably
re-routed to the caller (which is not your application) and it looks like
they get swallowed.


--
HTH
Stoitcho Goutsev (100)

In the simplified code below, shouldn't the thrown exception cause the
app to terminate since it is unhandled? It doesn't seem to do anything
in Debug or Release mode. I do get a first-chance exception message in
the debugger but that's it. Something seems to be intercepting the
exception and handling it...but I don't know what.

Any info would be appreciated
-sb



// Entire program
using System;
using System.Windows.Forms;

static class Program
{
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
}

public class Form1 : Form
{
public Form1()
{
this.AllowDrop = true;
this.DragDrop += new
System.Windows.Forms.DragEventHandler(this.Form1_DragDrop);
this.DragOver += new
System.Windows.Forms.DragEventHandler(this.Form1_DragOver);
}

private void Form1_DragOver(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Copy; // We'll accept any kind of
drop
}

private void Form1_DragDrop(object sender, DragEventArgs e)
{
throw new InvalidOperationException("DragDrop exception."); //
nothing happens here
}
}