C# Winform中无焦点状态下获取键盘输入或者USB扫描枪数据
下面的代码老是报错,哪位有经验的大神帮我看看~程序代码:
using System; using System.Collections.Generic; using System.Linq; using System.Runtime.InteropServices; using System.Text; namespace Common { 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(Assembly.GetExecutingAssembly().GetModules()[0]), 0); } return (hKeyboardHook != 0); } //卸载钩子 public bool Stop() { if (hKeyboardHook != 0) { return UnhookWindowsHookEx(hKeyboardHook); } return true; } } } 页面中用法: using System; using System.Collections.Generic; using 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"); } } } }扫描器是优力科的MS3398下面是扫描器的参数API
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