C#异步获取扫描枪信息

C#异步获取扫描枪信息仅一个类文件using System;using System.Collections.Generic;using System.Diagnostics;using System.Linq;using System.Reflection;using System.Runtime.InteropServices;using System.Text;namespace TakeNums{ /// <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 string BarCode;//条码信息 保存最终的条码 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); [DllImport("kernel32.dll")] public static extern IntPtr GetModuleHandle(string name); delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam); BarCodes barCode = new BarCodes(); int hKeyboardHook = 0; //string strBarCode = ""; StringBuilder sbBarCode = new StringBuilder(); 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) { //时间戳，大于50 毫秒表示手动输入 //strBarCode = barCode.Chr.ToString(); sbBarCode.Remove(0, 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 { sbBarCode.Append(barCode.Chr.ToString()); if ((msg.message & 0xff) == 13 && sbBarCode.Length > 3) {//回车 //barCode.BarCode = strBarCode; barCode.BarCode = sbBarCode.ToString();// barCode.OriginalBarCode; barCode.IsValid = true; sbBarCode.Remove(0, sbBarCode.Length); } //strBarCode = barCode.Chr.ToString(); } barCode.Time = DateTime.Now; try { if (BarCodeEvent != null && barCode.IsValid) { AsyncCallback callback = new AsyncCallback(AsyncBack); //object obj; Delegate[] delArray = BarCodeEvent.GetInvocationList(); //foreach (Delegate del in delArray) foreach (BardCodeDeletegate del in delArray) { try { //方法1 //obj = del.DynamicInvoke(barCode); //方法2 del.BeginInvoke(barCode, callback, del);//异步调用防止界面卡死 } catch (Exception ex) { throw ex; } } //BarCodeEvent(barCode);//触发事件 barCode.BarCode = ""; barCode.OriginalChrs = ""; barCode.OriginalAsciis = ""; barCode.OriginalBarCode = ""; } } catch (Exception) { throw; } finally { barCode.IsValid = false; //最后一定要 设置barCode无效 barCode.Time = DateTime.Now; } } } return CallNextHookEx(hKeyboardHook, nCode, wParam, lParam); } //异步返回方法 public void AsyncBack(IAsyncResult ar) { BardCodeDeletegate del = ar.AsyncState as BardCodeDeletegate; del.EndInvoke(ar); } //安装钩子 public bool Start() { if (hKeyboardHook == 0) { 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(13, hookproc, modulePtr, 0); } return (hKeyboardHook != 0); } //卸载钩子 public bool Stop() { if (hKeyboardHook != 0) { return UnhookWindowsHookEx(hKeyboardHook); } return true; } }}