C# snippets

winapi_send_close.cs

public static bool SendMessageToAllProcessWindows(uint processId, uint message = PInvoke.WM_CLOSE) {
    Process p = Process.GetProcessById((int)processId);
    PInvoke.PostMessage(new HWND(p.MainWindowHandle), message, 0, 0);
    bool sent = false;
    for (HWND hwnd = PInvoke.GetTopWindow(HWND.Null); !hwnd.IsNull; hwnd = PInvoke.GetWindow(hwnd, GET_WINDOW_CMD.GW_HWNDNEXT)) {
        unsafe {
            uint windowProcessId;
            _ = PInvoke.GetWindowThreadProcessId(hwnd, &windowProcessId);
            if (windowProcessId == processId) {
                _ = PInvoke.PostThreadMessage((uint)hwnd.Value, message, 0, 0);
                sent = true;
            }
        }
    }

    return sent;
}