C# Debugging problem when exception occurs

Question

Hi!

When I debug a C# program and I get an exception throwed (either thrown by code OR thrown by the framework), the IDE stops and get me to the corresponding line in my code.

Everything is fine for now.

I then press "F5" to continue. From this moment, it seams like I'm in an infinite loop. The IDE alway's get me back the the exception line. I have to Shift-F5 to get out of this.

I talked with some co-workers here and they told me that this happens sometime to them too.

Do you have an idea of what's happenning?

Thanks

vIceBerg

Answer 1

Once you get an exception Visual Studio (or whatever IDE you might be using) will not let you go any further unless the exception is handled in your code.

This behaviour is by design.

Answer 2

This is because the exception is un-handled and Visual Studio can not move past that line without it being handled in some manner. Simply put, it is by design.

One thing that you can do is drag and drop the execution point (yellow line/arrow) to a previous point in your code and modify the in memory values (using the Visual Studio watch windows) so that they do not cause an exception. Then start stepping through the code again*.

It is a better idea though to stop execution and fix the problem that is causing the exception, or properly handle the exception if the throw is not desired.

*This can have unintended consequences since you are essentially re-executing some code (not rewinding the execution).

Answer 3

An uncaught exception will bring down your app. Instead of this, VS will just keep you at the uncaught exception, You will have to terminate or backwind your app.

Answer 4

When the IDE breaks on the offending line of code, it stops just before executing the line that generated the exception. If you continue, it will just execute that line again, and get the exception again.

If you want to move past the error to see what would have happened, had the error not occurred, you can drag the yellow-highlighted line (the line that will execute next) down to the next line of code after the offending one. Of course, depending on what the offending line failed to do, your program may now be in a state that causes other errors, in which case you haven't really helped yourself much, and probably should fix your code so that the exception either doesn't occur, or is handled properly.