C#通过热键控制显示器开关的方法

            [DllImport("user32.dll  ", SetLastError = true)]
            public static extern bool UnregisterHotKey(
                   IntPtr hWnd,  // 要取消热键的窗口的句柄 
                    int id      // 要取消热键的ID 
                   );

            // 定义了辅助键的名称（将数字转变为字符以便于记忆，也可去除此枚举而直接使用数值） 
            [Flags()]
            public enum KeyModifiers
            {
                None = 0,
                Alt = 1,
                Ctrl = 2,
                Shift = 4,
                WindowsKey = 8
            }
        }

        protected override void WndProc(ref    Message m)
        {
            const int WM_HOTKEY = 0x0312;
            // 按快捷键   
            switch (m.Msg)
            {
                case WM_HOTKEY:
                    switch (m.WParam.ToInt32())
                    {