一段大局键盘钩子， 为什么实例化后不管用了，待高手帮忙

一段全局键盘钩子， 为什么实例化后不管用了，待高手帮忙

C# code

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;namespace WindowsFormsApplication1{    /// <summary>      /// Description of MainForm.      /// </summary>      public partial class KeyHook    {        //委托          public delegate int HookProc(int nCode, int wParam, IntPtr lParam);        static int hHook = 0;        public const int WH_KEYBOARD_LL = 13;        //LowLevel键盘截获，如果是WH_KEYBOARD＝2，并不能对系统键盘截取，Acrobat Reader会在你截取之前获得键盘。          HookProc KeyBoardHookProcedure;        //键盘Hook结构函数          [StructLayout(LayoutKind.Sequential)]        public class KeyBoardHookStruct        {            public int vkCode;            public int scanCode;            public int flags;            public int time;            public int dwExtraInfo;        }        #region DllImport        //设置钩子        [DllImport("user32.dll")]        public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]        //抽掉钩子        public static extern bool UnhookWindowsHookEx(int idHook);        [DllImport("user32.dll")]        //调用下一个钩子        public static extern int CallNextHookEx(int idHook, int nCode, int wParam, IntPtr lParam);        [DllImport("kernel32.dll")]        public static extern IntPtr GetModuleHandle(string name);        #endregion        #region 自定义事件        public void Hook_Start()        {            MessageBox.Show("安装键盘钩" + WH_KEYBOARD_LL + " hHook=" + hHook);            // 安装键盘钩子              if (hHook == 0)            {                KeyBoardHookProcedure = new HookProc(KeyBoardHookProc);                MessageBox.Show("KeyBoardHookProcedure=" + KeyBoardHookProcedure);                hHook = SetWindowsHookEx(WH_KEYBOARD_LL, KeyBoardHookProcedure, GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName), 0);                //如果设置钩子失败.                  if (hHook == 0)                {                    Hook_Clear();                    throw new Exception("设置Hook失败!");                }                MessageBox.Show("hHook=" + hHook);            }        }        //取消钩子事件          public void Hook_Clear()        {            bool retKeyboard = true;            if (hHook != 0)            {                retKeyboard = UnhookWindowsHookEx(hHook);                hHook = 0;            }            //如果去掉钩子失败.              if (!retKeyboard) throw new Exception("UnhookWindowsHookEx failed.");        }        //这里可以添加自己想要的信息处理          public static int KeyBoardHookProc(int nCode, int wParam, IntPtr lParam)        {            if (nCode >= 0)            {                KeyBoardHookStruct kbh = (KeyBoardHookStruct)Marshal.PtrToStructure(lParam, typeof(KeyBoardHookStruct));                if (kbh.vkCode == (int)Keys.X)                {                    MessageBox.Show("禁止驶入X键");                    return 1;                }            }            return CallNextHookEx(hHook, nCode, wParam, lParam);        }        #endregion    }}

C# code

KeyHook kh = new KeyHook();kh.Hook_Start();