用钩子获得按键信息实例

实例：实现获得按键信息

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();

}

}

}

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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[] { ' ', '\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。