using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Reflection; using System.Runtime.InteropServices; using System.Text; using System.Windows.Forms; namespace app01 {     public partial class Form1 : Form     {         public delegate int HookProc(int nCode, IntPtr wParam, IntPtr lParam);         //定义钩子句柄         public static int hHook = 0;         //定义钩子类型         public const int WH_MOUSE_LL = 14;         public HookProc MyProcedure;         //安装钩子         [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]         public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);         //卸载钩子         [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]         public static extern bool UnhookWindowsHookEx(int idHook);         //调用下一个钩子         [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]         public static extern int CallNextHookEx(int idHook, int nCode, IntPtr wParam, IntPtr lParam);         [StructLayout(LayoutKind.Sequential)]         public class POINT         {             public int x;             public int y;         }         [StructLayout(LayoutKind.Sequential)]         public class MouseHookStruct         {             public POINT pt;             public int hwnd;             public int wHitTestCode;             public int dwExtraInfo;         }         public Form1()         {             InitializeComponent();         }         private void button1_Click(object sender, EventArgs e)         {             if (hHook == 0)             {                 MyProcedure = new HookProc(this.MouseHookProc);                 //这里挂节钩子                 hHook = SetWindowsHookEx(WH_MOUSE_LL, MyProcedure, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0);                 if (hHook == 0)                 {                     MessageBox.Show("SetWindowsHookEx Failed");                     return;                 }                 button1.Text = "卸载钩子";             }             else             {                 bool ret = UnhookWindowsHookEx(hHook);                 if (ret == false)                 {                     MessageBox.Show("UnhookWindowsHookEx Failed");                     return;                 }                 hHook = 0;                 button1.Text = "安装钩子";             }         }         public int MouseHookProc(int nCode, IntPtr wParam, IntPtr lParam)         {             MouseHookStruct MyMouseHookStruct = (MouseHookStruct)Marshal.PtrToStructure(lParam, typeof(MouseHookStruct));             if (nCode < 0)             {                 return CallNextHookEx(hHook, nCode, wParam, lParam);             }             else             {                 String strCaption = "x = " + MyMouseHookStruct.pt.x.ToString("d") + "  y = " + MyMouseHookStruct.pt.y.ToString("d");                 this.Text = strCaption;                 return CallNextHookEx(hHook, nCode, wParam, lParam);             }         }     } }