I have the following method which is attempting to intercept a global press of ALT + Z:
private int KbHookProc(int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode >= 0)
{
var hookStruct = (KbLLHookStruct)Marshal.PtrToStructure(lParam, typeof(KbLLHookStruct));
bool altDown = GetKeyState(VK_ALT) != 0;
if (altDown)
{
if(hookStruct.vkCode == 0x5A) //alt + z
{
MessageBox.Show("ALT + Z");
}
}
}
return CallNextHookEx(_hookHandle, nCode, wParam, lParam);
}
This method almost works, however the message "ALT + Z" is shown twice every time I enter the key command.
Initially, I thought that I was capturing the event twice, once when Z was pressed and once when Z was released. I tried modifying the code to check the wParam variable to see if the event was a key up or down event.
public const int WM_KEYDOWN = 0x0100;
...
if(hookStruct.vkCode == 0x5A && wParam == (IntPtr)WM_KEYDOWN) //alt + z
{
MessageBox.Show("ALT + Z");
}
However, in this case no message is displayed when I enter the key command.
What am I missing here?
