本文实例讲述了C#使用钩子获得按键信息的方法。分享给大家供大家参考。具体如下：

窗体相关代码：

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;//键名 textBox2.Text = barCode.VirtKey.ToString();//虚拟码 textBox3.Text = barCode.ScanCode.ToString();//扫描码 textBox4.Text = barCode.AscII.ToString();//AscII textBox5.Text = barCode.Chr.ToString();//字符 textBox6.Text = barCode.IsValid ? barCode.BarCode : ""; //在这里进行键入值 } } 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(); } } }

后台类代码：

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; //虚拟码 public int ScanCode; //扫描码 public string KeyName; //键名 public uint AscII; //AscII 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; } // 安装钩子 [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)] private static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId); // 卸载钩子 [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)] private static extern bool UnhookWindowsHookEx(int idHook); // 继续下一个钩子 [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)] private static extern int CallNextHookEx(int idHook, int nCode, Int32 wParam, IntPtr lParam); //获取键名的字符串 [DllImport("user32", EntryPoint = "GetKeyNameText")] private static extern int GetKeyNameText(int lParam, StringBuilder lpBuffer, int nSize); //将256个虚拟键复制到指定的缓冲区中 [DllImport("user32", EntryPoint = "GetKeyboardState")] private static extern int GetKeyboardState(byte[] pbKeyState); //将指定的虚拟键码和键盘状态为相应的字符串 [DllImport("user32", EntryPoint = "ToAscii")] private static extern bool ToAscii(int VirtualKey, int ScanCode, byte[] lpKeyState, ref uint lpChar, int uFlags); //声明定义回调函数 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; //虚拟码 barCode.ScanCode = msg.paramL & 0xff; //扫描码 StringBuilder strKeyName = new StringBuilder(255); if (GetKeyNameText(barCode.ScanCode * 65536, strKeyName, 255) > 0) { barCode.KeyName = strKeyName.ToString().Trim(new char[] { ' ', '' }); } 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) //回车 { 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; } } }

【注意】要想测试实际的效果，必须执行编译后的Exe文件，在开发环境直接运行会没有效果的。

希望本文所述对大家的C#程序设计有所帮助。