【Net】一个简单的键盘钩子

最近在写一个采集程序

需要用到钩子

为了学习钩子 特写了个小demo

为实现高级功能的钩子打好基础

下面是代码

----------------

钩子类型

namespace CSharpHook
{
    public enum HookType
    {
        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
    }
}

钩子核心调用方法

amespace CSharpHook
{
    public delegate IntPtr HookProc(int code, IntPtr wparam, IntPtr lparam);
    public class CSHook
    {
        [DllImport("kernel32.dll")]
        public static extern int GetCurrentThreadId(); //取得当前线程编号的API

        [DllImport("User32.dll")]
        public extern static void UnhookWindowsHookEx(IntPtr handle); //取消Hook的API
        
        [DllImport("User32.dll")]
        public extern static IntPtr SetWindowsHookEx(int idHook, [MarshalAs(System.Runtime.InteropServices.UnmanagedType.FunctionPtr)] HookProc lpfn, IntPtr hinstance, int threadID);  //设置Hook的API

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

 钩子业务调用类

namespace CSharpHook
{
    public abstract class MyHookProcBase
    {
        protected IntPtr _nextHookPtr; //记录Hook编号
        protected CSharpHook.HookType hookType;
        protected int threadID;
        public void SetHook()
        {
            if (_nextHookPtr != IntPtr.Zero)
            {//已经勾过了
                return;
            }
            //CSharpHook.HookProc myhookProc = new CSharpHook.HookProc(this.Proc); //声明一个自己的Hook实现函数的委托对象

            _nextHookPtr = CSharpHook.CSHook.SetWindowsHookEx((int)hookType, new CSharpHook.HookProc(this.Proc), IntPtr.Zero, this.threadID); //加到Hook链中

        }

        public void UnHook()
        {

            if (_nextHookPtr != IntPtr.Zero)
            {

                CSharpHook.CSHook.UnhookWindowsHookEx(_nextHookPtr);//从Hook链中取消
                _nextHookPtr = IntPtr.Zero;
            }

        }
        protected abstract IntPtr Proc(int code, IntPtr wparam, IntPtr lparam);
    }

}

上面是一个类库

下面将创建一个Winform程序实现对本程序的键盘侦听

下面是代码

----------------

本程序具体的钩子业务逻辑

namespace HookTool
{
    public class MyHook : CSharpHook.MyHookProcBase
    {
        public int ThreadID
        {
            get {
                return base.threadID;
            }
            set {
                base.threadID = value;
            }
        } 
        public MyHook(CSharpHook.HookType ht) {
            base.hookType = ht;
        }
        public System.Windows.Forms.ListBox lbMsg;
        protected override IntPtr Proc(int code, IntPtr wparam, IntPtr lparam)
        {
            if (code < 0)
            {
                return CSharpHook.CSHook.CallNextHookEx(this._nextHookPtr, code, wparam, lparam); //返回，让后面的程序处理该消息
            }

            if ((lparam.ToInt32() & 0x40000000)>0)
            {
                //this.textBox1.Text = "a";
                this.lbMsg.Items.Add((char)wparam.ToInt32());
                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
            }
        }
    }
}

Winform主程序

namespace HookTool
{
    public partial class Hook : Form
    {
        MyHook mh;
        public Hook()
        {
            InitializeComponent();
        }

        private void Hook_Load(object sender, EventArgs e)
        {
            mh=new MyHook(CSharpHook.HookType.Keyboard);
            this.lvProcess.Columns.AddRange(new ColumnHeader[]{
                new ColumnHeader(){ Text="进程ID"},
                new ColumnHeader(){ Text="进程名称"},
                new ColumnHeader(){ Text="线程数"}
            });
            this.lvProcess.View = View.Details;
            GetProcess();
        }

        private void Hook_FormClosing(object sender, FormClosingEventArgs e)
        {
            mh.UnHook();
        }

        private void bMonitor_Click(object sender, EventArgs e)
        {
            mh.ThreadID = CSharpHook.CSHook.GetCurrentThreadId();
            mh.lbMsg = this.lbMsg;
            
            mh.SetHook();
        }
        void GetProcess() {
            this.lvProcess.Items.Clear();
            System.Diagnostics.Process[] ps=System.Diagnostics.Process.GetProcesses();
            foreach (System.Diagnostics.Process p in ps) {
                this.lvProcess.Items.Add(new ListViewItem(new string[]{
                    p.Id.ToString(),
                    p.ProcessName,
                    p.Threads.Count.ToString()
                }));
            }
        }

        private void bRefresh_Click(object sender, EventArgs e)
        {
            GetProcess();
        }

        private void bClose_Click(object sender, EventArgs e)
        {
            this.Close();
            System.Environment.Exit(0);
        }
    }
}

篇幅所限 不做详细说明