// 条码扫描器// 窗体部分相关代码：using System; using System.Collections.Generic;   using System.ComponentModel;   using System.Data;   using System.Drawing;   using System.Text;   using System.Windows.Forms;     namespace ReadBadCode   {       public partial class frmTest : Form       {           BarCodeHook BarCode = new BarCodeHook();           public frmTest()           {               InitializeComponent();               BarCode.BarCodeEvent += new BarCodeHook.BarCodeDelegate(BarCode_BarCodeEvent);           }             private delegate void ShowInfoDelegate(BarCodeHook.BarCodes barCode);           private void ShowInfo(BarCodeHook.BarCodes barCode)           {               if (this.InvokeRequired)               {                   this.BeginInvoke(new ShowInfoDelegate(ShowInfo), new object[] { barCode });               }               else              {                   textBox1.Text = barCode.KeyName;                   textBox2.Text = barCode.VirtKey.ToString();                   textBox3.Text = barCode.ScanCode.ToString();                   textBox4.Text = barCode.AscII.ToString();                   textBox5.Text = barCode.Chr.ToString();                   textBox6.Text = barCode.IsValid ? barCode.BarCode : "";               }           }             void BarCode_BarCodeEvent(BarCodeHook.BarCodes barCode)           {               ShowInfo(barCode);           }             private void frmTest_Load(object sender, EventArgs e)           {               BarCode.Start();           }             private void frmTest_FormClosed(object sender, FormClosedEventArgs e)           {               BarCode.Stop();           }             private void textBox6_TextChanged(object sender, EventArgs e)           {               if (textBox6.Text.Length > 0)               {                   MessageBox.Show(textBox6.Text);               }           }       }   }   BarCodeHook  类相关代码：using System;   using System.Collections.Generic;   using System.Text;   using System.Runtime.InteropServices;   using System.Reflection;     namespace ReadBadCode   {       public class BarCodeHook       {           public delegate void BarCodeDelegate(BarCodes barCode);           public event BarCodeDelegate BarCodeEvent;             public struct BarCodes           {               public int VirtKey;      //虚拟码               public int ScanCode;     //扫描码               public string KeyName;   //键名               public uint AscII;       //AscII               public char Chr;         //字符                 public string BarCode;   //条码信息               public bool IsValid;     //条码是否有效               public DateTime Time;    //扫描时间           }             private struct EventMsg           {               public int message;               public int paramL;               public int paramH;               public int Time;               public int hwnd;           }                     [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]           private static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);             [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]           private static extern bool UnhookWindowsHookEx(int idHook);             [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]           private static extern int CallNextHookEx(int idHook, int nCode, Int32 wParam, IntPtr lParam);             [DllImport("user32", EntryPoint = "GetKeyNameText")]           private static extern int GetKeyNameText(int lParam, StringBuilder lpBuffer, int nSize);             [DllImport("user32", EntryPoint = "GetKeyboardState")]           private static extern int GetKeyboardState(byte[] pbKeyState);             [DllImport("user32", EntryPoint = "ToAscii")]           private static extern bool ToAscii(int VirtualKey, int ScanCode, byte[] lpKeyState, ref uint lpChar, int uFlags);             delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);           BarCodes barCode = new BarCodes();           int hKeyboardHook = 0;           string strBarCode = "";             private int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)           {               if (nCode == 0)               {                   EventMsg msg = (EventMsg)Marshal.PtrToStructure(lParam, typeof(EventMsg));                     if (wParam == 0x100)   //WM_KEYDOWN = 0x100                   {                       barCode.VirtKey = msg.message & 0xff;  //虚拟码                       barCode.ScanCode = msg.paramL & 0xff;  //扫描码                         StringBuilder strKeyName = new StringBuilder(255);                       if (GetKeyNameText(barCode.ScanCode * 65536, strKeyName, 255) > 0)                       {                           barCode.KeyName = strKeyName.ToString().Trim(new char[] { ‘ ‘, ‘\0‘ });                       }                       else                      {                           barCode.KeyName = "";                       }                         byte[] kbArray = new byte[256];                       uint uKey = 0;                       GetKeyboardState(kbArray);                                                               if (ToAscii(barCode.VirtKey, barCode.ScanCode, kbArray, ref uKey, 0))                       {                           barCode.AscII = uKey;                           barCode.Chr = Convert.ToChar(uKey);                       }                         if (DateTime.Now.Subtract(barCode.Time).TotalMilliseconds > 50)                        {                           strBarCode = barCode.Chr.ToString();                       }                       else                      {                           if ((msg.message & 0xff) == 13 && strBarCode.Length > 3)   //回车                           {                               barCode.BarCode = strBarCode;                               barCode.IsValid = true;                           }                           strBarCode += barCode.Chr.ToString();                       }                         barCode.Time = DateTime.Now;                       if (BarCodeEvent != null) BarCodeEvent(barCode);    //触发事件                       barCode.IsValid = false;                   }               }               return CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);                     }                      // 安装钩子            public bool Start()           {               if (hKeyboardHook == 0)               {                   //WH_KEYBOARD_LL = 13                   hKeyboardHook = SetWindowsHookEx(13, new HookProc(KeyboardHookProc), Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0);               }               return (hKeyboardHook != 0);           }             // 卸载钩子            public bool Stop()           {               if (hKeyboardHook != 0)               {                   return UnhookWindowsHookEx(hKeyboardHook);               }               return true;           }       }