C# Winform中无焦点状态下获取键盘输入或者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;

}

}

复制代码

页面中用法：

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Text;

using System.Windows.Forms;

namespace Common

{

public partial class FrmMain : Form

{

BardCodeHooK BarCode = new BardCodeHooK();

public FrmMain()

{

InitializeComponent();

BarCode.BarCodeEvent += new BardCodeHooK.BardCodeDeletegate(BarCode_BarCodeEvent);

}

private delegate void ShowInfoDelegate(BardCodeHooK.BarCodes barCode);

private void ShowInfo(BardCodeHooK.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.Ascll.ToString();

textBox5.Text = barCode.Chr.ToString();

textBox6.Text = barCode.IsValid? barCode.BarCode : "";//是否为扫描枪输入，如果为true则是 否则为键盘输入

textBox7.Text += barCode.KeyName;

//MessageBox.Show(barCode.IsValid.ToString());

}

}

//C#中判断扫描枪输入与键盘输入

//Private DateTime _dt = DateTime.Now; //定义一个成员函数用于保存每次的时间点

//private void textBox1_KeyPress(object sender, KeyPressEventArgs e)

//{

// DateTime tempDt = DateTime.Now; //保存按键按下时刻的时间点

// TimeSpan ts = tempDt .Subtract(_dt); //获取时间间隔

// if (ts.Milliseconds > 50) //判断时间间隔，如果时间间隔大于50毫秒，则将TextBox清空

// textBox1.Text = "";

// dt = tempDt ;

//}

void BarCode_BarCodeEvent(BardCodeHooK.BarCodes barCode)

{

ShowInfo(barCode);

}

private void FrmMain_Load(object sender, EventArgs e)

{

BarCode.Start();

}

private void FrmMain_FormClosed(object sender, FormClosedEventArgs e)

{

BarCode.Stop();

}

private void textBox6_TextChanged(object sender, EventArgs e)

{

if (textBox6.Text.Length > 0)

{

MessageBox.Show("条码长度：" + textBox6.Text.Length + "\n条码内容：" + textBox6.Text, "系统提示");

}

}

}

}