Debug.Assert() only triggers when stepping over it

Question

I'm using Visual Studio 2010 to write a .NET assertion:

Debug.Assert(false, "Testing Debug.Assert");

When I put a breakpoint on this line of code, wait until the breakpoint hits, and then let the program continue to run, everything works fine: an "Assertion Failed" dialog pops up. However, when I remove the breakpoint and rerun the application, the Debug.Assert() statement is simply ignored.

Does anyone have an idea what might cause this very strange behavior?

Answer 1

A colleague of mine immediately knew what the problem was. I had to enable the "Enable Just My Code" flag at "Visual Studio 2010 / Menu / Options / Debugging / General". Apparently this is a bug in Visual Studio 2010".

Answer 2

I was experiencing the same problem. Using Trace.Assert works as expected.

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Well, Trace.Assert started exhibiting the same behavior on the next debugging session.

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Ah, found the problem.

• With 'Enable Just My Code" checked.

  • If 'Thrown' is checked for 'Common Language Runtime Exceptions' in the 'Exceptions' dialog (Ctrl+Alt+E), the Assert will be thrown.

  • If unchecked, the Assert will be thrown.

• With 'Enable Just My Code" unchecked.

  • If 'Thrown' checked, the Assert will not be thrown.

  • If 'Thrown' unchecked, the Assert will be thrown.

Therefore, the Assert will not be thrown when 'Enable Just My Code' is unchecked and 'Thrown' is checked for 'Common Language Runtime Exceptions'.