【实例简介】

【实例截图】

【核心代码】

using System;

using System.Collections.Generic;

using System.Linq;

using System.Runtime.InteropServices;

using System.Text;

//using System.Reflection;

namespace 获取扫描枪条码

{

public class BardCodeHooK

{

public delegate void BardCodeDeletegate(BarCodes barCode);

public event BardCodeDeletegate BarCodeEvent;

public struct BarCodes

{

public int VirtKey;//虚拟吗

public int ScanCode;//扫描码

public string KeyName;//键名

public uint Ascll;//Ascll

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 IParam, 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[] lpKeySate, 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;//虚拟吗

barCode.ScanCode = msg.paramL & 0xff;//扫描码

StringBuilder strKeyName = new StringBuilder(225);

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.Ascll = uKey;

barCode.Chr = Convert.ToChar(uKey);

}

TimeSpan ts = DateTime.Now.Subtract(barCode.Time);

if (ts.TotalMilliseconds > 50)

{

strBarCode = barCode.Chr.ToString();

}

else

{

if ((msg.message & 0xff) == 13 && strBarCode.Length > 3)

{

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(System.Reflection.Assembly.GetExecutingAssembly().GetModules()[0]), 0);

}

return (hKeyboardHook != 0);

}

//卸载钩子

public bool Stop()

{

if (hKeyboardHook != 0)

{

return UnhookWindowsHookEx(hKeyboardHook);

}

return true;

}

}

}