How to disable that an MFC application exits on pressing ESC or ALTF+F4?

Question

Hi!

I have an MFC application, which i don't want to be closed during the running. I have disabled the "X" icon in the right upper corner, but now if i press the ESC key, or ALT+F4 it still closes.

How can i disable this, so it won't close, if someone press those keys? After the program has finished running i want to reenable them.

Thanks,
kampi

Answer 1

Can't say for Esc key, but as far as Alt+F4 goes, it sends Close command to the main window. You basically need to override OnClose event and keep it empty (not call base method). That should do the trick.

P.S. Since I haven't touched MFC in many years, it may not be 100% true. Just how I remember it.

Answer 2

If you handle the WM_CLOSE message and throw it away. (i.e. Don't call DefWindowProc), then the window won't close.

You could also register the window class with the CS_NOCLOSE style, to disable all of the normal ways of closing the window.