C# winform键盘钩子

http://blog.163.com/da7_1@126/blog/static/1040726782011112652629750/

新建一个工程CSharpKeyboardHook，在WinForm窗体上拉一个Lable（用于显示，按下的是那个键）和两个button（用于开关勾子）

下面是C#winform键盘勾子的代码，照搬上去就可以的啦：

一、新建一个类文件KeyboardHookLib，代码如下所示：

using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using System.Reflection;
using System.Diagnostics;
using Microsoft.Win32;
using System.Windows.Forms;


namespace CSharpKeyboardHook
{

    /// 

    /// 键盘Hook管理类

    /// 
    public class KeyboardHookLib
    {
        private const int WH_KEYBOARD_LL = 13; //键盘

        //键盘处理事件委托.
        private delegate int HookHandle(int nCode, int wParam, IntPtr lParam);

        //客户端键盘处理事件
        public delegate void ProcessKeyHandle(HookStruct param, out bool handle);

        //接收SetWindowsHookEx返回值
        private static int _hHookValue = 0;

        //勾子程序处理事件
        private HookHandle _KeyBoardHookProcedure;

        //Hook结构
        [StructLayout(LayoutKind.Sequential)]
        public class HookStruct
        {
            public int vkCode;
            public int scanCode;
            public int flags;
            public int time;
            public int dwExtraInfo;
        }

        //设置钩子
        [DllImport("user32.dll")]
        private static extern int SetWindowsHookEx(int idHook, HookHandle lpfn, IntPtr hInstance, int threadId);

        //取消钩子
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        private static extern bool UnhookWindowsHookEx(int idHook);

        //调用下一个钩子
        [DllImport("user32.dll")]
        private static extern int CallNextHookEx(int idHook, int nCode, int wParam, IntPtr lParam);

        //获取当前线程ID
        [DllImport("kernel32.dll")]
        private static extern int GetCurrentThreadId();

        //Gets the main module for the associated process.
        [DllImport("kernel32.dll")]
        private static extern IntPtr GetModuleHandle(string name);

        private IntPtr _hookWindowPtr = IntPtr.Zero;

        //构造器
        public KeyboardHookLib() { }

        //外部调用的键盘处理事件
        private static ProcessKeyHandle _clientMethod = null;

        /// 

        /// 安装勾子
        /// 
        /// 外部调用的键盘处理事件
        public void InstallHook(ProcessKeyHandle clientMethod)
        {
            _clientMethod = clientMethod;

            // 安装键盘钩子
            if (_hHookValue == 0)
            {
                _KeyBoardHookProcedure = new HookHandle(GetHookProc);

                _hookWindowPtr = GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName);

                _hHookValue = SetWindowsHookEx(
                    WH_KEYBOARD_LL,
                    _KeyBoardHookProcedure,
                    _hookWindowPtr,
                    0);

                //如果设置钩子失败.
                if (_hHookValue == 0)

                       UninstallHook();
            }
        }

        //取消钩子事件
        public void UninstallHook()
        {
            if (_hHookValue != 0)
            {
                bool ret = UnhookWindowsHookEx(_hHookValue);
                if (ret) _hHookValue = 0;
            }
        }

        //钩子事件内部调用,调用_clientMethod方法转发到客户端应用。
        private static int GetHookProc(int nCode, int wParam, IntPtr lParam)
        {
            if (nCode >= 0)
            {
                //转换结构
                HookStruct hookStruct = (HookStruct)Marshal.PtrToStructure(lParam, typeof(HookStruct));

                if (_clientMethod != null)
                {
                    bool handle = false;
                    //调用客户提供的事件处理程序。
                    _clientMethod(hookStruct, out handle);
                    if (handle) return 1; //1:表示拦截键盘,return 退出
                }
            }
            return CallNextHookEx(_hHookValue, nCode, wParam, lParam);
        }

    }
}

///

//界面事件代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Reflection;
using System.Diagnostics;
using Microsoft.Win32;

namespace CSharpKeyboardHook
{
public partial class frmKeyboardHook : Form
{
//勾子管理类
private KeyboardHookLib _keyboardHook = null;

public frmKeyboardHook()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
//安装勾子
_keyboardHook = new KeyboardHookLib();
_keyboardHook.InstallHook(this.KeyPress);
}

private void button2_Click(object sender, EventArgs e)
{
//取消勾子
if (_keyboardHook != null) _keyboardHook.UninstallHook();
}

/// 

/// 客户端键盘捕捉事件.
/// 
/// 由Hook程序发送的按键信息
/// 是否拦截
public void KeyPress(KeyboardHookLib.HookStruct hookStruct, out bool handle)
{
handle = false; //预设不拦截任何键

if (hookStruct.vkCode == 91) // 截获左win(开始菜单键)
{
handle = true;
}

if (hookStruct.vkCode == 92)// 截获右win
{
handle = true;
}

//截获Ctrl+Esc
if (hookStruct.vkCode == (int)Keys.Escape && (int)Control.ModifierKeys == (int)Keys.Control)
{
handle = true;
}

//截获alt+f4
if (hookStruct.vkCode == (int)Keys.F4 && (int)Control.ModifierKeys == (int)Keys.Alt)
{
handle = true;
}

//截获alt+tab
if (hookStruct.vkCode == (int)Keys.Tab && (int)Control.ModifierKeys == (int)Keys.Alt)
{
handle = true;
}

//截获F1
if (hookStruct.vkCode == (int)Keys.F1)
{
handle = true;
}

//截获Ctrl+Alt+Delete
if ((int)Control.ModifierKeys == (int)Keys.Control + (int)Keys.Alt + (int)Keys.Delete)
{
handle = true;
}

//如果键A~Z
if (hookStruct.vkCode >= (int)Keys.A && hookStruct.vkCode <= (int)Keys.Z)
{
//挡掉G键，想要挡掉哪些键就把下面的G换成那个要挡掉的键，同理可以挡多个
if (hookStruct.vkCode == (int)Keys.G)
hookStruct.vkCode = (int)Keys.None; //设键为0

handle = true;
}

Keys key = (Keys)hookStruct.vkCode;
label1.Text = "你按下:" + (key == Keys.None ? "" : key.ToString());

}
}
}