鼠标和键盘的全局获一个类的详细介绍

用这个类的方法Start可以开始捕获键盘和鼠标的在全局事件和相应的参数信息，也就所谓的钩子程序：
以前见一个高人写的一个程序，开始看不明白，经过我的＂反译＂变的好理解了些，拿来和大家共享一下：

得到鼠标的消息的类：

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鼠标事件
/// 并且引发一个带MouseEventArgs参数的.NET鼠标事件以便你很容易使用这些信息
/// </summary>
/// <remarks>
/// </remarks>
public class MouseHook
{
private const int WM_MOUSEMOVE = 0x200;
private const int WM_LBUTTONDOWN = 0x201;
private const int WM_RBUTTONDOWN = 0x204;
private const int WM_MBUTTONDOWN = 0x207;
private const int WM_LBUTTONUP = 0x202;
private const int WM_RBUTTONUP = 0x205;
private const int WM_MBUTTONUP = 0x208;
private const int WM_LBUTTONDBLCLK = 0x203;
private const int WM_RBUTTONDBLCLK = 0x206;
private const int WM_MBUTTONDBLCLK = 0x209;

//全局的事件
public event MouseEventHandler OnMouseActivity;

static int hMouseHook = 0; //鼠标钩子句柄

//鼠标常量
public const int WH_MOUSE_LL = 14;//mouse hook constant

HookProc MouseHookProcedure; //声明鼠标钩子事件类型.

//声明一个Point的封送类型
[StructLayout(LayoutKind.Sequential)]
public class POINT
{
public int x;
public int y;
}

//声明鼠标钩子的封送结构类型
[StructLayout(LayoutKind.Sequential)]
public class MouseHookStruct
{
public POINT pt;
public int hWnd;
public int wHitTestCode;
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);

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.
/// </summary>
public MouseHook()
{
//Start();
}

//析构函数.
~MouseHook()
{
Stop();
}

public void Start()
{
//安装鼠标钩子
if(hMouseHook == 0)
{
//生成一个HookProc的实例.
MouseHookProcedure = new HookProc(MouseHookProc);

hMouseHook = SetWindowsHookEx( WH_MOUSE_LL, MouseHookProcedure, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0);

//如果装置失败停止钩子
if(hMouseHook == 0 )
{
Stop();
throw new Exception("SetWindowsHookEx failed.");
}
}
}

public void Stop()
{
bool retMouse =true;
if(hMouseHook != 0)
{
retMouse = UnhookWindowsHookEx(hMouseHook);
hMouseHook = 0;
}

//如果卸下钩子失败
if (!(retMouse)) throw new Exception("UnhookWindowsHookEx failed.");
}

private int MouseHookProc(int nCode, Int32 wParam, IntPtr lParam)
{
//如果正常运行并且用户要监听鼠标的消息
if ((nCode >= 0) && (OnMouseActivity!=null))
{
MouseButtons button=MouseButtons.None;
int clickCount=0;

switch (wParam)
{
case WM_LBUTTONDOWN:
button=MouseButtons.Left;
clickCount=1;
break;
case WM_LBUTTONUP:
button=MouseButtons.Left;
clickCount=1;
break;
case WM_LBUTTONDBLCLK:
button=MouseButtons.Left;
clickCount=2;
break;
case WM_RBUTTONDOWN:
button=MouseButtons.Right;
clickCount=1;
break;
case WM_RBUTTONUP:
button=MouseButtons.Right;
clickCount=1;
break;
case WM_RBUTTONDBLCLK:
button=MouseButtons.Right;
clickCount=2;
break;
}

//从回调函数中得到鼠标的信息
MouseHookStruct MyMouseHookStruct = (MouseHookStruct) Marshal.PtrToStructure(lParam, typeof(MouseHookStruct));
MouseEventArgs e=new MouseEventArgs(button, clickCount, MyMouseHookStruct.pt.x, MyMouseHookStruct.pt.y, 0 );
OnMouseActivity(this, e);
}
return CallNextHookEx(hMouseHook, nCode, wParam, lParam);
}
}
}

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);
}
}
}