C#.Netのグローバルキーボードフック技術

C#.Netのグローバルキーボードフック技術

///      ,              ,            ,       
///  : CSDN  hatita,  :[email protected],QQ:67913464 
///           2005-03-09 

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

namespace HookDll
{
 public class HookDll
 {
  private KBDLLHOOKSTRUCT kbdllhs; 
  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("  ,    !");
   }
  }

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