WPF 利用键盘钩子来捕获键盘,做一些不为人知的事情...完整实例

//安装钩子的函数 
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]

        public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);


        //卸下钩子的函数 

        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]

        public static extern bool UnhookWindowsHookEx(int idHook);


        //下一个钩挂的函数 
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]

        public static extern int CallNextHookEx(int idHook, int nCode, Int32 wParam, IntPtr lParam);

public class Win32Api
{
public const int WM_KEYDOWN = 0x100;

        public const int WM_KEYUP = 0x101;

        public const int WM_SYSKEYDOWN = 0x104;

        public const int WM_SYSKEYUP = 0x105;

        public const int WH_KEYBOARD_LL = 13;



        [StructLayout(LayoutKind.Sequential)] //声明键盘钩子的封送结构类型
        public class KeyboardHookStruct
        {

            public int vkCode; //表示一个在1到254间的虚似键盘码 

            public int scanCode; //表示硬件扫描码 

            public int flags;

            public int time;

            public int dwExtraInfo;

        }

public delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);

        //安装钩子的函数 
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);


        //卸下钩子的函数 

        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern bool UnhookWindowsHookEx(int idHook);


        //下一个钩挂的函数 
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern int CallNextHookEx(int idHook, int nCode, Int32 wParam, IntPtr lParam);

[DllImport("kernel32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        public static extern IntPtr GetModuleHandle(string lpModuleName);
}

public class KeyboardHook
    {
        int hHook;

        Win32Api.HookProc KeyboardHookDelegate;


/// <summary>
        /// 安装键盘钩子
        /// </summary>
        public void SetHook()
        {

            KeyboardHookDelegate = new Win32Api.HookProc(KeyboardHookProc);

            ProcessModule cModule = Process.GetCurrentProcess().MainModule;

            var mh = Win32Api.GetModuleHandle(cModule.ModuleName);

            hHook = Win32Api.SetWindowsHookEx(Win32Api.WH_KEYBOARD_LL, KeyboardHookDelegate, mh, 0);

        }

        /// <summary>
        /// 卸载键盘钩子
        /// </summary>
        public void UnHook()
        {

            Win32Api.UnhookWindowsHookEx(hHook);

        }
        
        /// <summary>
        /// 获取键盘消息
        /// </summary>
        /// <param name="nCode"></param>
        /// <param name="wParam"></param>
        /// <param name="lParam"></param>
        /// <returns></returns>
        private int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)
        {
            // 如果该消息被丢弃（nCode<0
            if (nCode >= 0)
            {

                Win32Api.KeyboardHookStruct KeyDataFromHook = (Win32Api.KeyboardHookStruct)Marshal.PtrToStructure(lParam, typeof(Win32Api.KeyboardHookStruct));

                int keyData = KeyDataFromHook.vkCode;

                //WM_KEYDOWN和WM_SYSKEYDOWN消息，将会引发OnKeyDownEvent事件
                if (OnKeyDownEvent != null && (wParam == Win32Api.WM_KEYDOWN || wParam == Win32Api.WM_SYSKEYDOWN))
                {
                        // 此处触发键盘按下事件
                        // keyData为按下键盘的值,对应 虚拟码

                }

                //WM_KEYUP和WM_SYSKEYUP消息，将引发OnKeyUpEvent事件 

                if (OnKeyUpEvent != null && (wParam == Win32Api.WM_KEYUP || wParam == Win32Api.WM_SYSKEYUP))
                {
                          // 此处触发键盘抬起事件
                }

            }

            return Win32Api.CallNextHookEx(hHook, nCode, wParam, lParam);

        }
}

namespace System.Windows.Input
{
    // 摘要: 
    //     提供在 Win32 虚拟键和 WPFSystem.Windows.Input.Key 枚举之间进行转换的静态方法。
    public static class KeyInterop
    {
        // 摘要: 
        //     将 Win32 虚拟键转换为 WPFSystem.Windows.Input.Key。
        //
        // 参数: 
        //   virtualKey:
        //     要转换的虚拟键。
        //
        // 返回结果: 
        //     WPF 键。
        public static Key KeyFromVirtualKey(int virtualKey);
        //
        // 摘要: 
        //     将 WPFSystem.Windows.Input.Key 转换为 Win32 虚拟键。
        //
        // 参数: 
        //   key:
        //     要转换的 WPF。
        //
        // 返回结果: 
        //     Win32 虚拟键。
        public static int VirtualKeyFromKey(Key key);
    }
}

KeyInterop.KeyFromVirtualKey(KeyData)