C# 鼠标全局钩子

/// <summary>
/// 鼠标全局钩子
/// </summary>
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;

/// <summary>
/// 点
/// </summary>
[StructLayout(LayoutKind.Sequential)]
public class POINT
{
public int x;
public int y;
}

/// <summary>
/// 钩子结构体
/// </summary>
[StructLayout(LayoutKind.Sequential)]
public class MouseHookStruct
{
public POINT pt;
public int hWnd;
public int wHitTestCode;
public int dwExtraInfo;
}

public const int WH_MOUSE_LL = 14; // mouse hook constant

// 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);

// 全局的鼠标事件
public event MouseEventHandler OnMouseActivity;

// 钩子回调函数
public delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);

// 声明鼠标钩子事件类型
private HookProc   _mouseHookProcedure;
private static int _hMouseHook = 0; // 鼠标钩子句柄

/// <summary>
/// 构造函数
/// </summary>
public MouseHook()
{

}

/// <summary>
/// 析构函数
/// </summary>
~MouseHook()
{
Stop();
}

/// <summary>
/// 启动全局钩子
/// </summary>
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(System.Reflection.Assembly.GetExecutingAssembly().GetModules()[0]), 0);

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

/// <summary>
/// 停止全局钩子
/// </summary>
public void Stop()
{
bool retMouse = true;

if (_hMouseHook != 0)
{
retMouse    = UnhookWindowsHookEx(_hMouseHook);
_hMouseHook = 0;
}

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

/// <summary>
/// 鼠标钩子回调函数
/// </summary>
private int MouseHookProc(int nCode, Int32 wParam, IntPtr lParam)
{
// 假设正常执行而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);

// 假设想要限制鼠标在屏幕中的移动区域能够在此处设置
// 后期须要考虑实际的x、y的容差
if(!Screen.PrimaryScreen.Bounds.Contains(e.X, e.Y))
{
//return 1;
}

OnMouseActivity(this, e);
}

// 启动下一次钩子
return CallNextHookEx(_hMouseHook, nCode, wParam, lParam);
}
}