得到键盘消息

来源：互联网发布：网络与新媒体好就业吗编辑：程序博客网时间：2024/05/17 08:13

得到键盘消息的类：

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

namespace HookGlobal
{

/// <summary>
/// 这个类可以让你得到一个在运行中程序的所有键盘或鼠标事件
/// 并且引发一个带KeyEventArgs和MouseEventArgs参数的.NET事件以便你很容易使用这些信息
/// </summary>
/// <remarks>
///  修改:lihx
///  修改时间:04.11.8
/// </remarks>
public class KeyBordHook
{
  private const int WM_KEYDOWN   = 0x100;
  private const int WM_KEYUP    = 0x101;
  private const int WM_SYSKEYDOWN  = 0x104;
  private const int WM_SYSKEYUP   = 0x105;

  //全局的事件
  public event KeyEventHandler OnKeyDownEvent;
  public event KeyEventHandler OnKeyUpEvent;
  public event KeyPressEventHandler OnKeyPressEvent;

  static int hKeyboardHook = 0; //键盘钩子句柄

  //鼠标常量
  public const int WH_KEYBOARD_LL = 13; //keyboard hook constant

  HookProc KeyboardHookProcedure; //声明键盘钩子事件类型.

  //声明键盘钩子的封送结构类型
  [StructLayout(LayoutKind.Sequential)]
   public class KeyboardHookStruct
  {
   public int vkCode; //表示一个在1到254间的虚似键盘码
   public int scanCode; //表示硬件扫描码
   public int flags;
   public int time;
   public int dwExtraInfo;
  }
  //装置钩子的函数
  [DllImport("user32.dll",CharSet=CharSet.Auto, CallingConvention=CallingConvention.StdCall)]
  public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);

  //卸下钩子的函数
  [DllImport("user32.dll",CharSet=CharSet.Auto, CallingConvention=CallingConvention.StdCall)]
  public static extern bool UnhookWindowsHookEx(int idHook);

  //下一个钩挂的函数
  [DllImport("user32.dll",CharSet=CharSet.Auto, CallingConvention=CallingConvention.StdCall)]
  public static extern int CallNextHookEx(int idHook, int nCode, Int32 wParam, IntPtr lParam);

  [DllImport("user32")]
  public static extern int ToAscii(int uVirtKey, int uScanCode, byte[] lpbKeyState,byte[] lpwTransKey, int fuState);

  [DllImport("user32")]
  public static extern int GetKeyboardState(byte[] pbKeyState);

  public delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);

  /// <summary>
  /// 墨认的构造函数构造当前类的实例并自动的运行起来.
  /// </summary>
  public KeyBordHook()
  {
   Start();
  }

  //析构函数.
  ~KeyBordHook()
  {
   Stop();
  }

  public void Start()
  {
   //安装键盘钩子
   if(hKeyboardHook == 0)
   {
    KeyboardHookProcedure = new HookProc(KeyboardHookProc);
    hKeyboardHook = SetWindowsHookEx( WH_KEYBOARD_LL, KeyboardHookProcedure, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0);

    if(hKeyboardHook == 0 )
    {
     Stop();
     throw new Exception("SetWindowsHookEx ist failed.");
    }
   }
  }

  public void Stop()
  {
   bool retKeyboard = true;

   if(hKeyboardHook != 0)
   {
    retKeyboard = UnhookWindowsHookEx(hKeyboardHook);
    hKeyboardHook = 0;
   }
   //如果卸下钩子失败
   if (!(retKeyboard)) throw new Exception("UnhookWindowsHookEx failed.");
  }

  private int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)
  {
   if ((nCode >= 0) && (OnKeyDownEvent!=null || OnKeyUpEvent!=null || OnKeyPressEvent!=null))
   {
    KeyboardHookStruct MyKeyboardHookStruct = (KeyboardHookStruct) Marshal.PtrToStructure(lParam, typeof(KeyboardHookStruct));
    //引发OnKeyDownEvent
    if ( OnKeyDownEvent!=null && ( wParam ==WM_KEYDOWN || wParam==WM_SYSKEYDOWN ))
    {
     Keys keyData=(Keys)MyKeyboardHookStruct.vkCode;
     KeyEventArgs e = new KeyEventArgs(keyData);
     OnKeyDownEvent(this, e);
    }

    //引发OnKeyPressEvent
    if ( OnKeyPressEvent!=null &&  wParam ==WM_KEYDOWN )
    {
     byte[] keyState = new byte[256];
     GetKeyboardState(keyState);

     byte[] inBuffer= new byte[2];
     if (ToAscii(MyKeyboardHookStruct.vkCode,
      MyKeyboardHookStruct.scanCode,
      keyState,
      inBuffer,
      MyKeyboardHookStruct.flags)==1)
     {
      KeyPressEventArgs e = new KeyPressEventArgs((char)inBuffer[0]);
      OnKeyPressEvent(this, e);
     }
    }

    //引发OnKeyUpEvent
    if ( OnKeyUpEvent!=null && ( wParam ==WM_KEYUP || wParam==WM_SYSKEYUP ))
    {
     Keys keyData=(Keys)MyKeyboardHookStruct.vkCode;
     KeyEventArgs e = new KeyEventArgs(keyData);
     OnKeyUpEvent(this, e);
    }
   }
   return CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);
  }
}
}