C#.Net的全局键盘钩子技术的详细介绍

///如未特别说明,本人所发表的技术文章都为原创, 任何人引用都请注明出处,并包含本声明 
///作者: CSDN网名hatita,邮件:hatita_qq@hotmail.com,QQ:67913464 
///向无名的开源英雄致敬 2005-03-09 

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

namespace HookDll
{
public class HookDll
{
private KBDLLHOOKSTRUCTkbdllhs;
private IntPtr iHookHandle=IntPtr.Zero;
private GCHandle _hookProcHandle;
public delegate IntPtr HookProc(int nCode, IntPtr wParam, IntPtr lParam);

[DllImport("user32.dll", CharSet=CharSet.Auto)]
public static extern IntPtr SetWindowsHookEx(int hookid, HookProc pfnhook, IntPtr hinst, int threadid);

[DllImport("user32.dll", CharSet=CharSet.Auto, ExactSpelling=true)]
public static extern bool UnhookWindowsHookEx(IntPtr hhook);

[DllImport("user32.dll", CharSet=CharSet.Auto, ExactSpelling=true)]
public static extern IntPtr CallNextHookEx(IntPtr hhook, int code, IntPtr wparam, IntPtr lparam);

[DllImport("kernel32.dll",CharSet=CharSet.Auto, CallingConvention=CallingConvention.StdCall)]
private static extern IntPtr GetModuleHandle(string lpModuleName);

[DllImport("Kernel32.dll",EntryPoint="RtlMoveMemory")] 
public static extern void CopyMemory (ref KBDLLHOOKSTRUCT Source,IntPtr Destination,int Length);

private const int WH_KEYBOARD = 13;

public void DisableKBDHook()
{
try
{
if (iHookHandle!=IntPtr.Zero)
{
UnhookWindowsHookEx(iHookHandle);
}
_hookProcHandle.Free();
iHookHandle = IntPtr.Zero;
}
catch
{
return;
}
}

public void EnableKBDHook()
{
HookProc hookProc= new HookProc(KBDDelegate);
_hookProcHandle= GCHandle.Alloc(hookProc);
iHookHandle= SetWindowsHookEx(WH_KEYBOARD, hookProc, GetModuleHandle("HookDll.dll"), 0);

if (iHookHandle == IntPtr.Zero) 
{
throw new System.Exception("错误,钩子失败!");
}
}

public IntPtr KBDDelegate(int iCode , IntPtr wParam,IntPtr lParam)
{
kbdllhs= new KBDLLHOOKSTRUCT();
CopyMemory(ref kbdllhs, lParam, 20);

//结果就在这里了^_^
int iHookCode= kbdllhs.vkCode;

DisableKBDHook();
EnableKBDHook();
return CallNextHookEx(iHookHandle, iCode, wParam,lParam);
}
}

[StructLayout(LayoutKind.Sequential)]
public struct KBDLLHOOKSTRUCT
{
public int vkCode;
public int scanCode;
public int flags;
public int time;
public int dwExtraInfo;
}
}