c#钩子学习笔记（一）

鼓捣了好大时候终于有一点眉目了，先看看代码吧

Hook类

using System;
using System.Runtime.InteropServices;
using System.Reflection;
using System.Threading;
using System.Windows.Forms;


namespace TestGouZi
{
    class HookClass
    {
　　　　　
        IntPtr _nextHookPtr; //记录Hook编号 
        internal enum HookType //枚举，钩子的类型 
        {

            MsgFilter = -1,

            JournalRecord = 0,

            JournalPlayback = 1,

            Keyboard = 2,

            GetMessage = 3,

            CallWndProc = 4,

            CBT = 5,

            SysMsgFilter = 6,

            Mouse = 7,

            Hardware = 8,

            Debug = 9,

            Shell = 10,

            ForegroundIdle = 11,

            CallWndProcRet = 12,

            KeyboardLL = 13,

            MouseLL = 14,

        };

        #region 引入api
        [DllImport("kernel32.dll")]
        static extern int GetCurrentThreadId(); //取得当前线程编号的API 

        [DllImport("User32.dll")]
        internal extern static void UnhookWindowsHookEx(IntPtr handle); //取消Hook的API 

        [DllImport("User32.dll")]
        internal extern static IntPtr SetWindowsHookEx(int idHook, [MarshalAs(UnmanagedType.FunctionPtr)] HookProc lpfn, IntPtr hinstance, int threadID); //设置Hook的API 

        [DllImport("User32.dll")]
        internal extern static IntPtr CallNextHookEx(IntPtr handle, int code, IntPtr wparam, IntPtr lparam); //取得下一个Hook的API 
        #endregion

        //声明一个委托
        internal delegate IntPtr HookProc(int code, IntPtr wparam, IntPtr lparam);

        //添加一个钩子处理过程
        IntPtr MyHookProc(int code, IntPtr wparam, IntPtr lparam)
        {
            if (code < 0) return CallNextHookEx(_nextHookPtr, code, wparam, lparam); //返回，让后面的程序处理该消息 
            if (wparam.ToInt32() == 98 || wparam.ToInt32() == 66) //如果用户输入的是 b 
            {
                MessageBox.Show("a");
                //this.textBox1.Text = "a";
                return (IntPtr)1; //直接返回了，该消息就处理结束了 
            }
            else
            {
                return IntPtr.Zero; //返回，让后面的程序处理该消息 
            }
        }

        #region 设置钩子、卸载钩子
        public void SetHook()
        {
            if (_nextHookPtr != IntPtr.Zero) //已经勾过了 
                return;
            HookProc myhookProc = new HookProc(MyHookProc); //声明一个自己的Hook实现函数的委托对象 
            _nextHookPtr = SetWindowsHookEx((int)HookType.Keyboard, myhookProc, IntPtr.Zero, GetCurrentThreadId()); //加到Hook链中 
        }

        public void UnHook()
        {
            if (_nextHookPtr != IntPtr.Zero)
            {
                UnhookWindowsHookEx(_nextHookPtr); //从Hook链中取消 
                _nextHookPtr = IntPtr.Zero;
            }
        }
        #endregion
    }
}

调用类

 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace TestGouZi
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        HookClass hc;
        private void button1_Click(object sender, EventArgs e)
        {
            hc = new HookClass();
            hc.SetHook();
        }

        private void Form1_FormClosing(object sender, FormClosingEventArgs e)
        {
            hc.UnHook();
        }      
    }
}

 

虽然实现的功能比较简单，但是比较适合像我这样的菜鸟入门，由于看了好多，大部分都感觉都比较复杂不适合入门。

可以参考下http://www.cnblogs.com/bfyx/archive/2012/10/31/2747744.html这个文章里的知识，理解起来会更好一点