Why does my MFC app hang when I throw an exception?

Question

If you throw an exception from inside an MFC dialog, the app hangs, even if you have a catch block in your code. It refuses to respond to the mouse or keyboard, and the on

Answer 1

The code for CDialog::DoModal makes the dialog modal by disabling the parent window. When the dialog code returns, the window is reenabled. There is an explicit catch for CException* errors, but not for any other kind of thrown exception; thus the parent window never gets reenabled.

Change your code to throw a pointer to any exception derived from CException, and you'll fix the problem.