BenHollis.net

I was working on XBList the other day when I hit a peculiarity of Visual Studio. I wanted to call a method asynchronously, so I was using BeginInvoke with a callback, as described in this article on MSDN. So I used BeginInvoke to fire off a method, and the method I invoked happened to throw an exception. I didn’t expect this to be a big deal – when the callback was called, I would call EndInvoke which would re-throw the exception and I could deal with it. However, while running in Visual Studio’s debugger, I got a break and an error dialog that claimed I had an unhandled exception. My code never made it to EndInvoke. It said something like “Exception unhandled by user code”.

It turns out that this is just some weirdness in Visual Studio. If you go to the Debug menu, choose “Exceptions…”, and uncheck “User-unhandled” for Common Language Runtime Exceptions, the exception will get properly thrown when EndInvoke is called, and everything’s fine.

It’s annoying that I have to give up the relatively useful unhandled-exception trapping that the Visual Studio debugger gives me, but I guess there’s no other way around it.

Tags: .NET, bug, C#, exceptions, Visual Studio

This entry was posted on Tuesday, January 13th, 2009 at 12:23 am and is filed under .NET. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.