本文實例講述了C#使用鉤子獲得按鍵信息的方法。分享給大家供大家參考。具體如下:
窗體相關代碼:
using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Runtime.InteropServices;using System.Threading;using ReadBadCode;namespace gouzi{ public partial class Form2 : Form {  BarCodeHook BarCode = new BarCodeHook();  public Form2()  {   InitializeComponent();   BarCode.BarCodeEvent += new BarCodeHook.BarCodeDelegate(BarCode_BarCodeEvent);  }  private delegate void ShowInfoDelegate(BarCodeHook.BarCodes barCode);  private void ShowInfo(BarCodeHook.BarCodes barCode)  {   if (this.InvokeRequired)   {    this.BeginInvoke(new ShowInfoDelegate(ShowInfo), new object[] { barCode });   }   else   {    textBox1.Text = barCode.KeyName;//鍵名    textBox2.Text = barCode.VirtKey.ToString();//虛擬碼    textBox3.Text = barCode.ScanCode.ToString();//掃描碼    textBox4.Text = barCode.AscII.ToString();//AscII    textBox5.Text = barCode.Chr.ToString();//字符    textBox6.Text = barCode.IsValid ? barCode.BarCode : "";    //在這里進行鍵入值   }  }  void BarCode_BarCodeEvent(BarCodeHook.BarCodes barCode)  {   ShowInfo(barCode);  }  private void Form2_Load(object sender, EventArgs e)  {   BarCode.Start();  }  private void Form2_StyleChanged(object sender, EventArgs e)  {   BarCode.Stop();  } }}后臺類代碼:
using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Runtime.InteropServices;using System.Reflection;namespace ReadBadCode{ class BarCodeHook {  public delegate void BarCodeDelegate(BarCodes barCode);  public event BarCodeDelegate BarCodeEvent;  public struct BarCodes  {   public int VirtKey;  //虛擬碼    public int ScanCode;  //掃描碼    public string KeyName; //鍵名    public uint AscII;  //AscII    public char Chr;   //字符   public string BarCode; //條碼信息    public bool IsValid;  //條碼是否有效    public DateTime Time; //掃描時間   }  private struct EventMsg  {   public int message;   public int paramL;   public int paramH;   public int Time;   public int hwnd;  }  // 安裝鉤子   [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]  private static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);  // 卸載鉤子  [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]  private static extern bool UnhookWindowsHookEx(int idHook);  // 繼續下一個鉤子  [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]  private static extern int CallNextHookEx(int idHook, int nCode, Int32 wParam, IntPtr lParam);  //獲取鍵名的字符串  [DllImport("user32", EntryPoint = "GetKeyNameText")]  private static extern int GetKeyNameText(int lParam, StringBuilder lpBuffer, int nSize);  //將256個虛擬鍵復制到指定的緩沖區中  [DllImport("user32", EntryPoint = "GetKeyboardState")]  private static extern int GetKeyboardState(byte[] pbKeyState);  //將指定的虛擬鍵碼和鍵盤狀態為相應的字符串  [DllImport("user32", EntryPoint = "ToAscii")]  private static extern bool ToAscii(int VirtualKey, int ScanCode, byte[] lpKeyState, ref uint lpChar, int uFlags);  //聲明定義回調函數  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; //虛擬碼      barCode.ScanCode = msg.paramL & 0xff; //掃描碼     StringBuilder strKeyName = new StringBuilder(255);     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.AscII = uKey;      barCode.Chr = Convert.ToChar(uKey);     }     if (DateTime.Now.Subtract(barCode.Time).TotalMilliseconds > 50)     {      strBarCode = barCode.Chr.ToString();     }     else     {      if ((msg.message & 0xff) == 13 && strBarCode.Length > 3)      //回車      {       barCode.BarCode = strBarCode;       barCode.IsValid = true;      }      strBarCode += barCode.Chr.ToString();     }     barCode.Time = DateTime.Now;     if (BarCodeEvent != null) BarCodeEvent(barCode);     //觸發事件      barCode.IsValid = false;    }   }   return CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);  }  // 安裝鉤子   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);  }  // 卸載鉤子   public bool Stop()  {   if (hKeyboardHook != 0)   {    return UnhookWindowsHookEx(hKeyboardHook);   }   return true;  } }}【注意】要想測試實際的效果,必須執行編譯后的Exe文件,在開發環境直接運行會沒有效果的。
希望本文所述對大家的C#程序設計有所幫助。
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