using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.Runtime.InteropServices; namespace **.Forms
{
/// <summary>
/// 获取键盘输入或者USB扫描枪数据 可以是没有焦点 应为使用的是全局钩子
/// USB扫描枪 是模拟键盘按下
/// 这里主要处理扫描枪的值，手动输入的值不太好处理
/// </summary>
public class BardCodeHook
{
public delegate void BardCodeDeletegate(BarCodes barCode);
public event BardCodeDeletegate BarCodeEvent; //定义成静态，这样不会抛出回收异常
private static HookProc hookproc; 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 OriginalChrs; //原始 字符
public string OriginalAsciis;//原始 ASCII public string OriginalBarCode; //原始数据条码 public bool IsValid;//条码是否有效
public DateTime Time;//扫描时间, public string BarCode;//条码信息 保存最终的条码
} private struct EventMsg
{
public int message;
public int paramL;
public int paramH;
public int Time;
public int hwnd;
} #region DllImport [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); [DllImport("kernel32.dll")]
public static extern IntPtr GetModuleHandle(string name);
#endregion delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);
BarCodes barCode = new BarCodes();
int hKeyboardHook = ;
StringBuilder sbBarCode = new StringBuilder(); private int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)
{
int i_calledNext = -;
if (nCode == )
{
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();
if (GetKeyNameText(barCode.ScanCode * , strKeyName, ) > )
{
barCode.KeyName = strKeyName.ToString().Trim(new char[] { ' ', '\0' });
}
else
{
barCode.KeyName = "";
}
byte[] kbArray = new byte[];
uint uKey = ;
GetKeyboardState(kbArray); if (ToAscii(barCode.VirtKey, barCode.ScanCode, kbArray, ref uKey, ))
{
barCode.Ascll = uKey;
barCode.Chr = Convert.ToChar(uKey); barCode.OriginalChrs += " " + Convert.ToString(barCode.Chr);
barCode.OriginalAsciis += " " + Convert.ToString(barCode.Ascll); barCode.OriginalBarCode += Convert.ToString(barCode.Chr); } TimeSpan ts = DateTime.Now.Subtract(barCode.Time); if (ts.TotalMilliseconds > )
{//时间戳，大于50 毫秒表示手动输入
sbBarCode.Remove(, sbBarCode.Length);
sbBarCode.Append(barCode.Chr.ToString()); barCode.OriginalChrs = " " + Convert.ToString(barCode.Chr);
barCode.OriginalAsciis = " " + Convert.ToString(barCode.Ascll); barCode.OriginalBarCode = Convert.ToString(barCode.Chr); }
else
{
if ((msg.message & 0xff) == && sbBarCode.Length > )
{//回车 barCode.BarCode = barCode.OriginalBarCode; barCode.IsValid = true;
sbBarCode.Remove(, sbBarCode.Length);
} sbBarCode.Append(barCode.Chr.ToString());
} try
{
if (BarCodeEvent != null && barCode.IsValid)
{ //barCode.BarCode = barCode.BarCode.Replace("\b", "").Replace("\0",""); 可以不需要 因为大于50毫秒已经处理
//先进行 WINDOWS事件往下传
i_calledNext = CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);
GC.KeepAlive(hookproc); BarCodeEvent(barCode);//触发事件 barCode.BarCode = ""; barCode.OriginalChrs = "";
barCode.OriginalAsciis = "";
barCode.OriginalBarCode = "";
}
}
catch
{
}
finally
{
barCode.IsValid = false; //最后一定要 设置barCode无效
barCode.Time = DateTime.Now;
}
}
}
if (i_calledNext == -)
{
i_calledNext = CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);
GC.KeepAlive(hookproc);
}
return i_calledNext;
} /// <summary>
/// 安装钩子
/// </summary>
/// <returns></returns>
public bool Start()
{
if (hKeyboardHook == )
{
hookproc = new HookProc(KeyboardHookProc); //GetModuleHandle 函数 替代 Marshal.GetHINSTANCE
//防止在 framework4.0中 注册钩子不成功
IntPtr modulePtr = GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName); //WH_KEYBOARD_LL=13
//全局钩子 WH_KEYBOARD_LL
// hKeyboardHook = SetWindowsHookEx(13, hookproc, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0); hKeyboardHook = SetWindowsHookEx(, hookproc, modulePtr, ); //IntPtr intPtr = Marshal.GetHINSTANCE(System.Reflection.Assembly.GetExecutingAssembly().GetModules()[0]);
//hKeyboardHook = SetWindowsHookEx(13, hookproc, intPtr, 0); GC.KeepAlive(hookproc);
}
return (hKeyboardHook != );
} /// <summary>
/// 卸载钩子
/// </summary>
/// <returns></returns>
public bool Stop()
{
if (hKeyboardHook != )
{
return UnhookWindowsHookEx(hKeyboardHook);
}
return true;
} }
}
使用方法：
private void Form_Load(object sender, EventArgs e)
{
bardCodeHook.Start();
bardCodeHook.BarCodeEvent += bardCodeHook_BarCodeEvent;
} private void Form_FormClosed(object sender, FormClosedEventArgs e)
{
bardCodeHook.Stop();
bardCodeHook.BarCodeEvent -= bardCodeHook_BarCodeEvent;
}