C#中通过设置钩子监视鼠标移动

这个问题来自论坛提问，C#的大致代码如下

using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace WindowsApplication1
...{
public partial class Form1 : Form
...{
public Form1()
...{
InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
...{
Win32Hook hook = new Win32Hook();
hook.onMouseChange += new EventHandler(hook_onMouseChange);
hook.SetHook();
}

void hook_onMouseChange(object sender, EventArgs e)
...{
this.Text = Cursor.Position.ToString();
}
}
public class Win32Hook
...{

[DllImport("kernel32")]
public static extern int GetCurrentThreadId();

[DllImport("user32",CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern int SetWindowsHookEx(
HookType idHook,
HOOKPROC lpfn,
int hmod,
int dwThreadId);

public enum HookType
...{
WH_GETMESSAGE = 3
}

public delegate int HOOKPROC(int nCode, int wParam, int lParam);

public event System.EventHandler onMouseChange;

public void SetHook()
...{
SetWindowsHookEx(HookType.WH_GETMESSAGE,
new HOOKPROC(this.MyKeyboardProc),
0,
GetCurrentThreadId());
}

public int MyKeyboardProc(int nCode, int wParam, int lParam)
...{
if (onMouseChange != null)
...{
onMouseChange(null, null);
}
return 0;
}
}
}