/// <summary>
/// 獲取鍵盤輸入或者USB掃描槍數據 可以是沒有焦點 應為使用的是全局鈎子
/// USB掃描槍 是模擬鍵盤按下
/// 這里主要處理掃描槍的值，手動輸入的值不太好處理
/// </summary>
public class BardCodeHooK
{
public delegate void BardCodeDeletegate(BarCodes barCode);
public event BardCodeDeletegate BarCodeEvent;
//定義成靜態，這樣不會拋出回收異常
private static HookProc hookproc;
public struct BarCodes
{
public int VirtKey;//虛擬嗎
public int ScanCode;//掃描碼
public string KeyName;//鍵名
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; //原始數據條碼
public bool IsValid;//條碼是否有效
public DateTime Time;//掃描時間,
public string BarCode;//條碼信息 保存最終的條碼
}
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;//虛擬嗎
barCode.ScanCode = msg.paramL & 0xff;//掃描碼
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)
{//時間戳，大於50 毫秒表示手動輸入
// 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)
{//回車
// 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 因為大於50毫秒已經處理
//先進行 WINDOWS事件往下傳
i_calledNext = CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);
BarCodeEvent(barCode);//觸發事件
barCode.BarCode = "";
barCode.OriginalChrs = "";
barCode.OriginalAsciis = "";
barCode.OriginalBarCode = "";
}
}
catch { }
finally
{
barCode.IsValid = false; //最后一定要 設置barCode無效
barCode.Time = DateTime.Now;
}
}
}
if (i_calledNext == -10)
{
i_calledNext = CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);
}
return i_calledNext;
}
//安裝鈎子
public bool Start()
{
if (hKeyboardHook == 0)
{
hookproc = new HookProc(KeyboardHookProc);
//GetModuleHandle 函數 替代 Marshal.GetHINSTANCE
//防止在 framework4.0中 注冊鈎子不成功
IntPtr modulePtr = GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName);
//WH_KEYBOARD_LL=13
//全局鈎子 WH_KEYBOARD_LL
// hKeyboardHook = SetWindowsHookEx(13, hookproc, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0);
hKeyboardHook = SetWindowsHookEx(13, hookproc, modulePtr, 0);
}
return (hKeyboardHook != 0);
}
//卸載鈎子
public bool Stop()
{
if (hKeyboardHook != 0)
{
return UnhookWindowsHookEx(hKeyboardHook);
}
return true;
}
}
頁面中用法：
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 : "";//是否為掃描槍輸入，如果為true則是 否則為鍵盤輸入
textBox7.Text += barCode.KeyName;
//MessageBox.Show(barCode.IsValid.ToString());
}
}
//C#中判斷掃描槍輸入與鍵盤輸入
//Private DateTime _dt = DateTime.Now; //定義一個成員函數用於保存每次的時間點
//private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
//{
// DateTime tempDt = DateTime.Now; //保存按鍵按下時刻的時間點
// TimeSpan ts = tempDt .Subtract(_dt); //獲取時間間隔
// if (ts.Milliseconds > 50) //判斷時間間隔，如果時間間隔大於50毫秒，則將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("條碼長度：" + textBox6.Text.Length + "\n條碼內容：" + textBox6.Text, "系統提示");
}
}
}
}
轉載：http://www.cnblogs.com/Hdsome/archive/2011/11/15/2227717.html