I am trying to send some simple mouse down/up messages to Windows Calculator using SendMessage. I have been able to press the buttons by sending the messages to the buttons directly. However, I have not been able to successfully send the same messages to the main calculator window handle. Given that hWnd is the window handle to calculator, this is my code.
IntPtr fiveKey = FindWindowEx(hWnd, IntPtr.Zero, "Button", "5");
int x = 5; // X coordinate of the click
int y = 5; // Y coordinate of the click
IntPtr lParam = (IntPtr)((y << 16) | x); // The coordinates
IntPtr wParam = IntPtr.Zero; // Additional parameters for the click (e.g. Ctrl)
const uint downCode = 0x201; // Left click down code
const uint upCode = 0x202; // Left click up code
SendMessage(fiveKey, downCode, wParam, lParam); // Mouse button down
SendMessage(fiveKey, upCode, wParam, lParam); // Mouse button up
Can anyone explain to me why sending the messages to hWnd instead of fiveKey with the x/y offsets changed to the position of the "5" key does not work? I would like to eventually use this code to simulate mouse clicks on a different application that doesn't have buttons like calculator.