钩子(Hook),是Windows消息处理机制的一个平台,应用程序可以在上面设置子程以监视指定窗口的某种消息,而且所监视的窗口可以是其他进程所创建的。当消息到达后,在目标窗口处理函数之前处理它。钩子机制允许应用程序截获处理window消息或特定事件。
关于Hook的一些介绍可以参考http://www.cnblogs.com/bfyx/archive/2012/10/31/2747744.html
我是菜鸟入门,该系列文章主要记录钩子学习的一点一滴
下面给个简单的应用看看,很简单,比较适合像我这样的入门菜鸟
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
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();
}
}
}