获取键盘输入或者USB扫描枪数据

/// <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;
} [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)
{
int i_calledNext = -10;
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 (barCode.KeyName.Equals("A") || barCode.KeyName.Equals("a"))
// {
if (ToAscii(barCode.VirtKey, barCode.ScanCode, kbArray, ref uKey, 0))
{
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 > 30)
{//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
{
if ((msg.message & 0xff) == 13 && sbBarCode.Length > 3)
{//回车
// barCode.BarCode = strBarCode;
// barCode.BarCode = sbBarCode.ToString(); barCode.BarCode = barCode.OriginalBarCode; barCode.IsValid = true;
//strBarCode = "";
sbBarCode.Remove(0, sbBarCode.Length);
}
// //strBarCode += barCode.Chr.ToString();// updated by dragon 20141124
sbBarCode.Append(barCode.Chr.ToString());
//strBarCode += barCode.KeyName;
// strBarCode += barCode.VirtKey.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); 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 == -10)
{
i_calledNext = CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);
}
return i_calledNext;
} //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;
} }