The easiest way to do that is to use the function SetWindowsHookEx(WH_CBT, fun, NULL, GetCurrentThreadId())
. Then the fun
function, a callback defined by you, will be called when a number of events happen. The one you want is the HCBT_CREATEWND
.
Somethink like that (totally untested):
HWND hDllHandle = NULL;
LRESULT CALLBACK X_CBTProc(int nCode, WPARAM wParam, LPARAM lParam)
{
if (nCode == HCBT_CREATEWND)
hDllHandle = (HWND)wParam;
return CallNextHookEx(NULL, nCode, wParam, lParam); //The first parameter is useless
}
HWND CallXAndGetHWND()
{
HHOOK hDllHook = SetWindowsHookEx(WH_CBT, X_CBTProc, NULL, GetCurrentThreadId());
X();
UnhookWindowsHookEx(hDllHook);
//hDllHandle is a global variable, so will be now you window!
return hDllHandle;
}
Note that this function is not thread-aware, but most likely you will call it just once at the beginning of your code, so it shouldn't matter.
And beware! Many functions, even Win32 API functions, create hidden windows. This code will hook all of them and return the last one to be created. Changing it to return any other, or even a list of them, if needed, should be trivial.