Closing the window delays if a mouse hook is set

Question

If I set a low level mouse hook, WH_MOUSE_LL,
when I click the [x] (Close) button the window delays ~500ms and then it disappears.

Do you know what causes the delay? And, is there a way to fix it?

(the window and the hook are created with direct calls to win32 api in C++)

score 1 · Answer 1 · answered Jan 05 '10 at 12:25

1

WH_MOUSE_LL is a different kind of hook from most other ones. It is implemented by calling the hook procedure directly rather than injecting a DLL. That requires a message loop to be actively pumping. The odds that there isn't one anymore after you close a window are high. Be sure to unhook in the WM_CLOSE message handler.

answered Jan 05 '10 at 12:25

Hans Passant

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@nobugz, I've tried your solution, and other combinations, but it didn't work. It's a normal (main) window with a message loop. With `WH_KEYBOARD_LL` I don't have that problem. – Nick Dandoulakis Jan 05 '10 at 12:31
I can't guess what the problem might be without seeing repro code. Post it to a file sharing service somewhere. – Hans Passant Jan 05 '10 at 12:40
No repro, it instantly closes. This suggests the problem is external. – Hans Passant Jan 05 '10 at 13:35
ok, thanks for helping. Did you try it on Windows XP or on newer version? – Nick Dandoulakis Jan 05 '10 at 13:53

Closing the window delays if a mouse hook is set

1 Answers1