WinForm和WPF中注册热键

由于.Net没有提供专门的类库处理热键，所以需要直接调用windows API来解决。

HotKey为.NET调用Windows API的封装代码，主要是RegisterHotKey和UnregisterHotKey

    class HotKey
    {
        /// <summary>
        /// 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。.NET方法:Marshal.GetLastWin32Error()
        /// </summary>
        /// <param name="hWnd">要定义热键的窗口的句柄</param>
        /// <param name="id">定义热键ID（不能与其它ID重复） </param>
        /// <param name="fsModifiers">标识热键是否在按Alt、Ctrl、Shift、Windows等键时才会生效</param>
        /// <param name="vk">定义热键的内容,WinForm中可以使用Keys枚举转换，
        /// WPF中Key枚举是不正确的,应该使用System.Windows.Forms.Keys枚举，或者自定义正确的枚举或int常量</param>
        /// <returns></returns>
        [DllImport("user32.dll", SetLastError = true)]
        public static extern bool RegisterHotKey(
        IntPtr hWnd,
        int id,
        KeyModifiers fsModifiers,
        int vk
        );
        /// <summary>
        /// 取消注册热键
        /// </summary>
        /// <param name="hWnd">要取消热键的窗口的句柄</param>
        /// <param name="id">要取消热键的ID</param>
        /// <returns></returns>
        [DllImport("user32.dll", SetLastError = true)]
        public static extern bool UnregisterHotKey(
        IntPtr hWnd,
        int id
        );
        /// <summary>
        /// 向全局原子表添加一个字符串，并返回这个字符串的唯一标识符,成功则返回值为新创建的原子ID,失败返回0
        /// </summary>
        /// <param name="lpString"></param>
        /// <returns></returns>
        [DllImport("kernel32", SetLastError = true)]
        public static extern short GlobalAddAtom(string lpString);
        [DllImport("kernel32", SetLastError = true)]
        public static extern short GlobalDeleteAtom(short nAtom);
        /// <summary>
        /// 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）
        /// </summary>
        [ComVisible(true)]
        [Flags]
        [TypeConverter(typeof(KeysConverter))]
        public enum KeyModifiers
        {
            None = 0,
            Alt = 1,
            Ctrl = 2,
            Shift = 4,
            WindowsKey = 8
        }
    }

　　Windows Form中调用代码

        private void Form1_Activated(object sender, EventArgs e)
        {
            HotKey.RegisterHotKey(Handle, 102, HotKey.KeyModifiers.Alt | HotKey.KeyModifiers.Ctrl, Keys.S);
            HotKey.RegisterHotKey(Handle, 100, HotKey.KeyModifiers.Shift, Keys.S);

        }

        private void Form1_Leave(object sender, EventArgs e)
        {
            HotKey.UnregisterHotKey(Handle, 102);
            HotKey.UnregisterHotKey(Handle, 100);
        }

        ///
        /// 监视Windows消息
        /// 重载WndProc方法，用于实现热键响应
        ///
        ///
        protected override void WndProc(ref Message m)
        {
            const int WM_HOTKEY = 0x0312;//如果m.Msg的值为0x0312那么表示用户按下了热键
            //按快捷键
            switch (m.Msg)
            {
                case WM_HOTKEY:
                    switch (m.WParam.ToInt32())
                    {
                        case 100:    //按下的是Shift+S
                            //此处填写快捷键响应代码
                            MessageBox.Show("按下的是Shift+S");
                            break;
                        case 101:    //按下的是Ctrl+B
                            //此处填写快捷键响应代码
                            break;
                        case 102:    //按下的是Ctrl+Alt+S
                            CaptureImageTool capture = new CaptureImageTool();

                            if (capture.ShowDialog() == DialogResult.OK)
                            {
                                Image image = capture.Image;
                                pictureBox1.Width = image.Width;
                                pictureBox1.Height = image.Height;
                                pictureBox1.Image = image;
                            }
                            break;
                    }
                    break;
            }
            base.WndProc(ref m);
        }

　　WPF中窗口句柄需要借助WindowInteropHelper来得到，处理函数的加入和Winform不同，需要HwndSource来添加处理函数。

        void MainWindow_Unloaded(object sender, RoutedEventArgs e)
        {
            UnRegisterHotKey();
        }

        void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            RegisterHotKey();
        }

        private void UnRegisterHotKey()
        {
            IntPtr handle = new WindowInteropHelper(this).Handle;
            int id = 1000;
            bool r = HotKey.UnregisterHotKey(handle, id);

            HotKey.UnregisterHotKey(handle, 102);
            HotKey.UnregisterHotKey(handle, 100);
        }

        private void RegisterHotKey()
        {
            IntPtr handle = new WindowInteropHelper(this).Handle;
            int id = 1000;
            bool r = HotKey.RegisterHotKey(handle, id, HotKey.KeyModifiers.Ctrl, (int)System.Windows.Forms.Keys.F12);

            HotKey.RegisterHotKey(handle, 102, HotKey.KeyModifiers.Alt | HotKey.KeyModifiers.Ctrl, (int)Keys.S);
            HotKey.RegisterHotKey(handle, 100, HotKey.KeyModifiers.Shift, (int)Keys.S);

            //获得消息源
            System.Windows.Interop.HwndSource source = System.Windows.Interop.HwndSource.FromHwnd(handle);

            source.AddHook(HotKeyHook);
        }
        static private IntPtr HotKeyHook(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
        //热键处理过程
        {
            const int WM_HOTKEY = 0x0312;//如果m.Msg的值为0x0312那么表示用户按下了热键
            if (msg == WM_HOTKEY)
            {
                switch (wParam.ToInt32())
                {
                    case 100:    //按下的是Shift+S
                        //此处填写快捷键响应代码
                        MessageBox.Show("按下的是Shift+S");
                        break;
                    case 101:    //按下的是Ctrl+B
                        //此处填写快捷键响应代码
                        break;
                    case 102:    //按下的是Ctrl+Alt+S
                        break;
                }
            }
            return IntPtr.Zero;
        }