C#全局热键设置与窗体热键设置实例

private void FrmMain_KeyDown(object sender, KeyEventArgs e)
{
    if (e.Alt && e.Shift && e.Control && e.KeyCode == Keys.S)
    {
 MessageBox.Show("我按了Control +Shift +Alt +S");
    }
}

public class AppHotKey
{
        [DllImport("kernel32.dll")]
        public static extern uint GetLastError();
        //如果函数执行成功，返回值不为0。
        //如果函数执行失败，返回值为0。要得到扩展错误信息，调用GetLastError。
        [DllImport("user32.dll", SetLastError = true)]
        public static extern bool RegisterHotKey(
            IntPtr hWnd,                //要定义热键的窗口的句柄
            int id,                     //定义热键ID（不能与其它ID重复）          
            KeyModifiers fsModifiers,   //标识热键是否在按Alt、Ctrl、Shift、Windows等键时才会生效
            Keys vk                     //定义热键的内容
            );

        [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
        }
        ///

        /// 注册热键
        ///

        /// 窗口句柄
        /// 热键ID
        /// 组合键
        /// 热键
        public static void RegKey(IntPtr hwnd, int hotKey_id, KeyModifiers keyModifiers, Keys key)
        {
            try
            {
                if (!RegisterHotKey(hwnd, hotKey_id, keyModifiers, key))
                {
                    if (Marshal.GetLastWin32Error() == 1409) { MessageBox.Show("热键被占用 ！"); }
                    else
                    {
                        MessageBox.Show("注册热键失败！");
                    }
                }
            }
            catch (Exception) { }
        }
        ///

        /// 注销热键
        ///

        /// 窗口句柄
        /// 热键ID
        public static void UnRegKey(IntPtr hwnd, int hotKey_id)
        {
            //注销Id号为hotKey_id的热键设定
            UnregisterHotKey(hwnd, hotKey_id);
        }
}