C ++如何使程序全局检测我的击键？

Question

I'm making a program and I want it to detect whenever I press F6 and then call an if statement. This should work globally, not just when I'm focused on my program. How can I do that?

Answer 1

Since you're on Windows, you can set up a keyboard hook using SetWindowsHookEx with WH_KEYBOARD or WH_KEYBOARD_LL . Then process keypresses in your matching KeyboardProc or LowLevelKeyboardProc function, and filter out any F6 presses. Make sure you call CallNextHookEx for any non-F6 keypress, since failing to call CallNextHookEx will "eat" the keyboard message.

You'll want to do this in a DLL; you'll need both 32-bit and 64-bit versions of the DLL, since 32-bit apps can only be injected with a 32-bit DLL and 64-bit apps can only be injected with a 64-bit DLL.

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You could also try something based around RegisterHotKey . This is somewhat safer than a hook, although if another application calls RegisterHotKey and specifies F6 before yours does, you won't be able to register the hotkey.

Since you don't want any extra modifiers on your hotkey, the call would look something like this:

RegisterHotKey(myHwnd, 1, 0, VK_F6);

where myHwnd is the HWND of your window (or optionally nullptr if you'd rather process the WM_HOTKEY messages in your message loop), 1 is the identifier of the hotkey and can be whatever int you like, 0 specifies no modifier keys (Ctrl, Alt, Windows key, etc.), and VK_F6 is the virtual keycode for F6.

Answer 2

The function you need is RegisterHotKey(VK_F6 ...) , and it will cause WM_HOTKEY to be sent. You'll therefore need a Windows message loop.