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[C#.Net]全局钩子实现USB扫码枪无焦点状态下扫入

时间:2018-12-11 21:53:16      阅读:489      评论:0      收藏:0      [点我收藏+]

标签:连续   版本   声明   复制   spec   runtime   cond   决定   rsh   

1.扫描枪获取数据原理基本相当于键盘数据,获取扫描枪扫描出来的数据,一般分为两种实现方式。

  a)文本框输入获取焦点,扫描后自动显示在文本框内。

  b)使用键盘钩子,勾取扫描枪虚拟按键,根据按键频率进行手动输入和扫描枪扫描判断。

2.要实现系统钩子其实很简单,调用三个Win32的API即可。

SetWindowsHookEx 用于设置钩子。(设立一道卡子,盘查需要的信息)

CallNextHookEx 用于传递钩子(消息是重要的,所以从哪里来,就应该回到哪里去,除非你决定要封锁消息)

UnhookWindowsHookEx 卸载钩子(卸载很重要,卡子设多了会造成拥堵)

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Text;
  4 using System.Runtime.InteropServices;
  5 using System.Reflection;
  6 using System.Diagnostics;
  7 namespace SaomiaoTest2
  8 {
  9     /// <summary>
 10     /// 获取键盘输入或者USB扫描枪数据 可以是没有焦点 应为使用的是全局钩子
 11     /// USB扫描枪 是模拟键盘按下
 12     /// 这里主要处理扫描枪的值,手动输入的值不太好处理
 13     /// </summary>
 14    public class BardCodeHooK
 15     {
 16         public delegate void BardCodeDeletegate(BarCodes barCode);
 17         public event BardCodeDeletegate BarCodeEvent;
 18 
 19         //定义成静态,这样不会抛出回收异常
 20         private static HookProc hookproc;
 21 
 22 
 23         public struct BarCodes
 24         {
 25             public int VirtKey;//虚拟吗
 26             public int ScanCode;//扫描码
 27             public string KeyName;//键名
 28             public uint Ascll;//Ascll
 29             public char Chr;//字符
 30 
 31             public string BarCode;//条码信息   保存最终的条码
 32             public bool IsValid;//条码是否有效
 33             public DateTime Time;//扫描时间,
 34         }
 35 
 36         private struct EventMsg
 37         {
 38             public int message;
 39             public int paramL;
 40             public int paramH;
 41             public int Time;
 42             public int hwnd;
 43         }
 44 
 45         [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
 46         private static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);
 47 
 48         [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
 49         private static extern bool UnhookWindowsHookEx(int idHook);
 50 
 51         [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
 52         private static extern int CallNextHookEx(int idHook, int nCode, Int32 wParam, IntPtr lParam);
 53 
 54         [DllImport("user32", EntryPoint = "GetKeyNameText")]
 55         private static extern int GetKeyNameText(int IParam, StringBuilder lpBuffer, int nSize);
 56 
 57         [DllImport("user32", EntryPoint = "GetKeyboardState")]
 58         private static extern int GetKeyboardState(byte[] pbKeyState);
 59 
 60         [DllImport("user32", EntryPoint = "ToAscii")]
 61         private static extern bool ToAscii(int VirtualKey, int ScanCode, byte[] lpKeySate, ref uint lpChar, int uFlags);
 62 
 63         [DllImport("kernel32.dll")]
 64         public static extern IntPtr GetModuleHandle(string name);
 65 
 66 
 67         delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);
 68         BarCodes barCode = new BarCodes();
 69         int hKeyboardHook = 0;
 70         string strBarCode = "";
 71 
 72         private int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)
 73         {
 74             if (nCode == 0)
 75             {
 76                 EventMsg msg = (EventMsg)Marshal.PtrToStructure(lParam, typeof(EventMsg));
 77                 if (wParam == 0x100)//WM_KEYDOWN=0x100
 78                 {
 79                     barCode.VirtKey = msg.message & 0xff;//虚拟吗
 80                     barCode.ScanCode = msg.paramL & 0xff;//扫描码
 81                     StringBuilder strKeyName = new StringBuilder(225);
 82                     if (GetKeyNameText(barCode.ScanCode * 65536, strKeyName, 255) > 0)
 83                     {
 84                         barCode.KeyName = strKeyName.ToString().Trim(new char[] {  , \0 });
 85                     }
 86                     else
 87                     {
 88                         barCode.KeyName = "";
 89                     }
 90                     byte[] kbArray = new byte[256];
 91                     uint uKey = 0;
 92                     GetKeyboardState(kbArray);
 93 
 94 
 95                     if (ToAscii(barCode.VirtKey, barCode.ScanCode, kbArray, ref uKey, 0))
 96                     {
 97                         barCode.Ascll = uKey;
 98                         barCode.Chr = Convert.ToChar(uKey);
 99                     }
100 
101                     TimeSpan ts = DateTime.Now.Subtract(barCode.Time);
102 
103                     if (ts.TotalMilliseconds > 50)
104                     {//时间戳,大于50 毫秒表示手动输入
105                         strBarCode = barCode.Chr.ToString();
106                     }
107                     else
108                     {
109                         if ((msg.message & 0xff) == 13 && strBarCode.Length > 3)
110                         {//回车
111                             barCode.BarCode = strBarCode;
112                             barCode.IsValid = true;
113                         }
114                         strBarCode += barCode.Chr.ToString();
115                     }
116                     barCode.Time = DateTime.Now;
117                     if (BarCodeEvent != null)
118                         BarCodeEvent(barCode);//触发事件
119                     barCode.IsValid = false;
120                 }
121             }
122             return CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);
123         }
124 
125         //安装钩子
126         public bool Start()
127         {
128             if (hKeyboardHook == 0)
129             {
130                 hookproc = new HookProc(KeyboardHookProc);
131 
132 
133                 //GetModuleHandle 函数 替代 Marshal.GetHINSTANCE
134                 //防止在 framework4.0中 注册钩子不成功
135                 IntPtr modulePtr = GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName);
136 
137                 //WH_KEYBOARD_LL=13
138                 //全局钩子 WH_KEYBOARD_LL
139                 //  hKeyboardHook = SetWindowsHookEx(13, hookproc, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0);
140 
141                 hKeyboardHook = SetWindowsHookEx(13, hookproc, modulePtr, 0);
142             }
143             return (hKeyboardHook != 0);
144         }
145 
146         //卸载钩子
147         public bool Stop()
148         {
149             if (hKeyboardHook != 0)
150             {
151                 return UnhookWindowsHookEx(hKeyboardHook);
152             }
153             return true;
154         }
155     }
156 }

在实践过程中,发现版本一的代码只能扫描条形码,如伴随二维码中的字母出现就不能正确获取数据。

版本二:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Text;

namespace BarcodeScanner
{
    public class ScanerHook
    {
        public delegate void ScanerDelegate(ScanerCodes codes);
        public event ScanerDelegate ScanerEvent;

       //private const int WM_KEYDOWN = 0x100;//KEYDOWN
              //private const int WM_KEYUP = 0x101;//KEYUP
              //private const int WM_SYSKEYDOWN = 0x104;//SYSKEYDOWN
              //private const int WM_SYSKEYUP = 0x105;//SYSKEYUP
//private static int HookProc(int nCode, Int32 wParam, IntPtr lParam);
        private int hKeyboardHook = 0;//声明键盘钩子处理的初始值
        private ScanerCodes codes = new ScanerCodes();//13为键盘钩子
        //定义成静态,这样不会抛出回收异常
        private static HookProc hookproc;
        delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
     //设置钩子
        private static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
      //卸载钩子
        private static extern bool UnhookWindowsHookEx(int idHook);
        [DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
        //继续下个钩子
        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")]
      //获取按键的状态
        private static extern int GetKeyboardState(byte[] pbKeyState);
        [DllImport("user32", EntryPoint = "ToAscii")]
      //ToAscii职能的转换指定的虚拟键码和键盘状态的相应字符或字符
        private static extern bool ToAscii(int VirtualKey, int ScanCode, byte[] lpKeySate, ref uint lpChar, int uFlags);
    
      //int VirtualKey //[in] 指定虚拟关键代码进行翻译。
      //int uScanCode, // [in] 指定的硬件扫描码的关键须翻译成英文。高阶位的这个值设定的关键,如果是(不压)
      //byte[] lpbKeyState, // [in] 指针,以256字节数组,包含当前键盘的状态。每个元素(字节)的数组包含状态的一个关键。如果高阶位的字节是一套,关键是下跌(按下)。在低比特,如/果设置表明,关键是对切换。在此功能,只有肘位的CAPS LOCK键是相关的。在切换状态的NUM个锁和滚动锁定键被忽略。
      //byte[] lpwTransKey, // [out] 指针的缓冲区收到翻译字符或字符。
      //uint fuState); // [in] Specifies whether a menu is active. This parameter must be 1 if a menu is active, or 0 otherwise.

        
            
        [DllImport("kernel32.dll")]
     //使用WINDOWS API函数代替获取当前实例的函数,防止钩子失效
        public static extern IntPtr GetModuleHandle(string name);
        public ScanerHook()
        {
        }
        public bool Start()
        {
            if (hKeyboardHook == 0)
            {
                hookproc = new HookProc(KeyboardHookProc);
                //GetModuleHandle 函数 替代 Marshal.GetHINSTANCE  
                //防止在 framework4.0中 注册钩子不成功  
                IntPtr modulePtr = GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName);
                //WH_KEYBOARD_LL=13  
                //全局钩子 WH_KEYBOARD_LL  
                //  hKeyboardHook = SetWindowsHookEx(13, hookproc, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]), 0);  
                hKeyboardHook = SetWindowsHookEx(13, hookproc, modulePtr, 0);
            }
            return (hKeyboardHook != 0);
        }
        public bool Stop()
        {
            if (hKeyboardHook != 0)
            {
               bool  retKeyboard = UnhookWindowsHookEx(hKeyboardHook);
                hKeyboardHook = 0;
                return retKeyboard;
               
            }
            return true;
        }
        private int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)
        {
           
          
            EventMsg msg = (EventMsg)Marshal.PtrToStructure(lParam, typeof(EventMsg));
            codes.Add(msg);
            if (ScanerEvent != null && msg.message == 13 && msg.paramH > 0 && !string.IsNullOrEmpty(codes.Result))
            {
                ScanerEvent(codes);
            }
             return CallNextHookEx(hKeyboardHook, nCode, wParam, lParam);
        }
        public class ScanerCodes
        {
            private int ts = 100; // 指定输入间隔为300毫秒以内时为连续输入  
            private List<List<EventMsg>> _keys = new List<List<EventMsg>>();
            private List<int> _keydown = new List<int>();   // 保存组合键状态  
            private List<string> _result = new List<string>();  // 返回结果集  
            private DateTime _last = DateTime.Now;
            private byte[] _state = new byte[256];
            private string _key = string.Empty;
            private string _cur = string.Empty;
            public EventMsg Event
            {
                get
                {
                    if (_keys.Count == 0)
                    {
                        return new EventMsg();
                    }
                    else
                    {
                        return _keys[_keys.Count - 1][_keys[_keys.Count - 1].Count - 1];
                    }
                }
            }
            public List<int> KeyDowns
            {
                get
                {
                    return _keydown;
                }
            }
            public DateTime LastInput
            {
                get
                {
                    return _last;
                }
            }
            public byte[] KeyboardState
            {
                get
                {
                    return _state;
                }
            }
            public int KeyDownCount
            {
                get
                {
                    return _keydown.Count;
                }
            }
            public string Result
            {
                get
                {
                    if (_result.Count > 0)
                    {
                        return _result[_result.Count - 1].Trim();
                    }
                    else
                    {
                        return null;
                    }
                }
            }
            public string CurrentKey
            {
                get
                {
                    return _key;
                }
            }
            public string CurrentChar
            {
                get
                {
                    return _cur;
                }
            }
            public bool isShift
            {
                get
                {
                    return _keydown.Contains(160);
                }
            }
            public void Add(EventMsg msg)
            {
                #region 记录按键信息           

                // 首次按下按键  
                if (_keys.Count == 0)
                {
                    _keys.Add(new List<EventMsg>());
                    _keys[0].Add(msg);
                    _result.Add(string.Empty);
                }
                // 未释放其他按键时按下按键  
                else if (_keydown.Count > 0)
                {
                    _keys[_keys.Count - 1].Add(msg);
                }
                // 单位时间内按下按键  
                else if (((TimeSpan)(DateTime.Now - _last)).TotalMilliseconds < ts)
                {
                    _keys[_keys.Count - 1].Add(msg);
                }
                // 从新记录输入内容  
                else
                {
                    _keys.Add(new List<EventMsg>());
                    _keys[_keys.Count - 1].Add(msg);
                    _result.Add(string.Empty);
                }
                #endregion
                _last = DateTime.Now;
                #region 获取键盘状态
                // 记录正在按下的按键  
                if (msg.paramH == 0 && !_keydown.Contains(msg.message))
                {
                    _keydown.Add(msg.message);
                }
                // 清除已松开的按键  
                if (msg.paramH > 0 && _keydown.Contains(msg.message))
                {
                    _keydown.Remove(msg.message);
                }
                #endregion
                #region 计算按键信息
            
               int v = msg.message & 0xff;
                int c = msg.paramL & 0xff;
                StringBuilder strKeyName = new StringBuilder(500);
                if (GetKeyNameText(c * 65536, strKeyName, 255) > 0)
                {
                    _key = strKeyName.ToString().Trim(new char[] {  , \0 });
                    GetKeyboardState(_state);
                    if (_key.Length == 1 && msg.paramH == 0)// && msg.paramH == 0
                    {
                        // 根据键盘状态和shift缓存判断输出字符  
                        _cur = ShiftChar(_key, isShift, _state).ToString();
                        _result[_result.Count - 1] += _cur;
                    }
              // 备选
             else
                    {
                        _cur = string.Empty;
                    }
                }
                #endregion
            }
            private char ShiftChar(string k, bool isShiftDown, byte[] state)
            {
                bool capslock = state[0x14] == 1;
                bool numlock = state[0x90] == 1;
                bool scrolllock = state[0x91] == 1;
                bool shiftdown = state[0xa0] == 1;
                char chr = (capslock ? k.ToUpper() : k.ToLower()).ToCharArray()[0];
                if (isShiftDown)
                {
                    if (chr >= a && chr <= z)
                    {
                     chr = (char)((int)chr - 32);
                    }
                    else if (chr >= A && chr <= Z)
                    {
                        if (chr==Z)
                        {
                            string s = "";
                        }
                        chr = (char)((int)chr + 32);
                    }                   
                    else
                    {                      
                        string s = "`1234567890-=[];‘,./";
                        string u = "~!@#$%^&*()_+{}:\"<>?";
                        if (s.IndexOf(chr) >= 0)
                        {
                            return (u.ToCharArray())[s.IndexOf(chr)];
                        }
                    }
                }
                return chr;
            }
        }
        public struct EventMsg
        {
            public int message;
            public int paramL;
            public int paramH;
            public int Time;
            public int hwnd;
        }
    }
}

版本二中的代码,实践中发现出现了获取扫描数据却省略“+”加号的情况出现。

因此在版本二中备选处添加

//判断是+ 强制添加+
                    else if (_key.Length == 5 && msg.paramH == 0&&msg.paramL==78&&msg.message==107)// && msg.paramH == 0
                    {
                        // 根据键盘状态和shift缓存判断输出字符  
                        _cur = Convert.ToChar(+).ToString();
                        _result[_result.Count - 1] += _cur;
                    }

3.winform在无焦点情况下的使用方式:

using BarcodeScanner;
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;

namespace BarCodeTest
{
    public partial class Form1 : Form
    {
        private ScanerHook listener = new ScanerHook();  
        public Form1()
        {
            InitializeComponent();
            listener.ScanerEvent += Listener_ScanerEvent;  
        }
        private void Listener_ScanerEvent(ScanerHook.ScanerCodes codes)
        {
            textBox3.Text = codes.Result;         
        }  
        private void Form1_Load(object sender, EventArgs e)
        {
            listener.Start();  
        }

        private void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            listener.Stop();  
        }  
    }
}

其实上面的代码都是复制这位大侠的,真心觉得大侠太厉害了,解决多年的疑惑,保留纪念

https://www.cnblogs.com/TBW-Superhero/p/8659306.html

[C#.Net]全局钩子实现USB扫码枪无焦点状态下扫入

标签:连续   版本   声明   复制   spec   runtime   cond   决定   rsh   

原文地址:https://www.cnblogs.com/masonlu/p/10105135.html

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