Simulate ALT+F4 key press in C++

Question

I`m making a c++ application with the KINECT. I basically want to use it to send alt f4 to close the current focused window not my application, as you would normally pressing alt f4 on the keboard. Thanks in advance.

Im already using VkKeyScanA to input a few other keys but i just cant find the key code for alr+f4

Answer 1

There's more than one way to do this. Emulating keystrokes is the last thing you should do, very hard to get right since you cannot control the keyboard state of the process well enough.

First one is GetForegroundWindow + SendMessage to send the WM_SYSCOMMAND, SC_CLOSE command. Which is what Alt+F4 does when it is processed by the default window procedure. Which in turn sends WM_CLOSE by default if the program did not override the WM_SYSCOMMAND processing.

If you create your own window then you should favor avoiding trying to find the foreground window. Send WM_APPCOMMAND with the APPCOMMAND_CLOSE command to your own window. Your call to DefWindowProc() forwards the command through several layers to the shell.

In case you are considering a more forceful way, like WM_CLOSE then do review Raymond Chen's recent blog post.