C#操控 条形码扫描枪

// 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;  
        }  
    }  


本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/yefanqiu/archive/2009/05/03/4146580.aspx#