C# 串口模拟键盘输入

      最近遇到一个需求：需要在网站的文本输入栏上输入条码和回车； 查了一下资料，记录如下：

     最后的方案： 两台电脑用串口连接，从A机器发送信息到串口， B机器从串口读到信息，并模拟键盘输出。 

  

public class CKeyController
   {
       [System.Runtime.InteropServices.DllImport("user32")]
       static extern void keybd_event(
           byte bVk,
           byte bScan,
           uint dwFlags,
           uint dwExtraInfo
           );
       const uint KEYEVENTF_EXTENDEDKEY = 0x1;
       const uint KEYEVENTF_KEYUP = 0x2;
       private static Dictionary<string, byte> keycode = new Dictionary<string, byte>();

       [DllImport("user32.dll")]
       public static extern int SendMessage(IntPtr hWnd, int Msg, int wParam, int lParam);
       [DllImport("User32.DLL")]
       public static extern int SendMessage(IntPtr hWnd,uint Msg, int wParam, string lParam);
       [DllImport("User32.DLL")]
       public static extern int SendMessage(IntPtr hWnd, uint Msg, int wParam, int lParam);

       [DllImport("User32.DLL")]
       public static extern IntPtr FindWindowEx(IntPtr hwndParent,
           IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
       public const uint WM_SETTEXT = 0x000C;
       public const uint WM_CHAR = 0x0102;
       public static int WM_KEYDOWN = 0x0100;
       //释放一个键
       public static int WM_KEYUP = 0x0101;

       public void InitKey()
       {
           keycode = new Dictionary<string, byte>();
           keycode.Add("A", 65);
           keycode.Add("B", 66);
           keycode.Add("C", 67);
           keycode.Add("D", 68);
           keycode.Add("E", 69);
           keycode.Add("F", 70);
           keycode.Add("G", 71);
           keycode.Add("H", 72);
           keycode.Add("I", 73);
           keycode.Add("J", 74);
           keycode.Add("K", 75);
           keycode.Add("L", 76);
           keycode.Add("M", 77);
           keycode.Add("N", 78);
           keycode.Add("O", 79);
           keycode.Add("P", 80);
           keycode.Add("Q", 81);
           keycode.Add("R", 82);
           keycode.Add("S", 83);
           keycode.Add("T", 84);
           keycode.Add("U", 85);
           keycode.Add("V", 86);
           keycode.Add("W", 87);
           keycode.Add("X", 88);
           keycode.Add("Y", 89);
           keycode.Add("Z", 90);
           keycode.Add("0", 48);
           keycode.Add("1", 49);
           keycode.Add("2", 50);
           keycode.Add("3", 51);
           keycode.Add("4", 52);
           keycode.Add("5", 53);
           keycode.Add("6", 54);
           keycode.Add("7", 55);
           keycode.Add("8", 56);
           keycode.Add("9", 57);
           keycode.Add(".", 0x6E);
           keycode.Add("LEFT", 0x25);
           keycode.Add("UP", 0x26);
           keycode.Add("RIGHT", 0x27);
           keycode.Add("DOWN", 0x28);
           keycode.Add("-", 0x6D);
           keycode.Add("{ENTER}", 13);
       }

       public static void KeyBoardDo(string key)
       {
           keybd_event(keycode[key], 0x45, KEYEVENTF_EXTENDEDKEY | 0, 0);
           keybd_event(keycode[key], 0x45, KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP, 0);
       }

       /// <summary>
       /// 使用keybd_event发送。 缺点是不能指定接受的窗口名称；接受窗口必须为当前活动窗口。
       /// </summary>
       /// <param name="barcode"></param>
       public void SendBarcode(string barcode)
       {
           for (int k = 0; k < barcode.Length; k++)
           {
               string ak = barcode.Substring(k, 1);
               KeyBoardDo(ak);
           }
           KeyBoardDo("{ENTER}");
       }


       /// <summary>
       ///
       /// </summary>
       /// <param name="barcode"></param>
       public void SendKeys(string barcode)
       {
           System.Windows.Forms.SendKeys.Send(barcode);
           System.Windows.Forms.SendKeys.Send("{ENTER}");
       }


       /// <summary>
       ///可以指定窗口，并且窗口可以为不活动状态； 即应用程序不在显示器最上层。
       /// </summary>
       /// <param name="hello"></param>
       public void SendKeyByMessage(string hello)
       {
           System.Diagnostics.Process[] GamesProcess = System.Diagnostics.Process.GetProcessesByName("notepad");
           if (GamesProcess.Length == 0) return;

           IntPtr hWnd = FindWindowEx(GamesProcess[0].MainWindowHandle,
           IntPtr.Zero, "Edit", null);

           //SendMessage(hWnd, WM_SETTEXT, 0, hello); //清空记事本中内容；写入字符；并且光标回到第一行第一个位置。
           int key = 0;
           for (int k = 0; k < hello.Length; k++)
           {
               string ak = hello.Substring(k, 1);
               key = keycode[ak];
               SendMessage(hWnd, WM_CHAR, key, 0);
           }

           key = keycode["{ENTER}"];
           SendMessage(hWnd, WM_CHAR, key, 0);      //往记事本中添加内容。
       }

   }

  类中有3中将字符串输出的功能:

1. 

keybd_event: 不能指定输出对象

2. <pre name="code" class="csharp"><pre name="code" class="csharp">SendMessage(hWnd, WM_CHAR, key, 0);

输出一个字符到指定的窗口。

<pre name="code" class="csharp">SendMessage(hWnd, WM_SETTEXT, 0, hello);

清空记事本中内容；写入字符；并且光标回到第一行第一个位置。

3. <pre name="code" class="csharp">SendKeys

这个一直没有实验成功，一直会有软件不响应；除非使用手动激活其他窗口。 具体原因没有细查。

串口控制代码

<pre name="code" class="csharp"> public class CComController
    {
        private SerialPort sp = null;

        /// <summary>
        /// 打开串口
        /// </summary>
        /// <param name="protName">串口号</param>
        /// <param name="baudRate">波特率</param>
        /// <param name="dataBit">数据位</param>
        /// <param name="stopBits">停止位</param>
        /// /// <param name="parity">校验位</param>
        /// <returns></returns>
        public bool OpenCom(string protName, int baudRate, int dataBit, float stopBits, int parity)
        {
            bool flag = true;
            if (sp == null)
            {
                sp = new SerialPort();
            }
            sp.PortName = protName;//串口号
            sp.BaudRate = baudRate;//波特率
            sp.ReadTimeout = 10;
            float f = stopBits;//停止位
            if (f == 0)
            {
                sp.StopBits = StopBits.None;
            }
            else if (f == 1.5)
            {
                sp.StopBits = StopBits.OnePointFive;
            }
            else if (f == 1)
            {
                sp.StopBits = StopBits.One;
            }
            else
            {
                sp.StopBits = StopBits.Two;
            }

            sp.DataBits = dataBit;//数据位

            if (parity == 0)
            {
                sp.Parity = Parity.None;
            }
            else if (parity == 1)
            {
                sp.Parity = Parity.Odd;
            }
            else if (parity == 2)
            {
                sp.Parity = Parity.Even;
            }
            else
            {
                sp.Parity = Parity.None;
            }

            try
            {
                if (!sp.IsOpen)
                {
                    sp.Open();
                }
            }
            catch (Exception)
            {
                flag = false;
            }
            return flag;
        }

        /// <summary>
        /// 关闭端口
        /// </summary>
        /// <returns></returns>
        public bool CloseCom()
        {
            try
            {
                if (sp.IsOpen)
                {
                    sp.Close();
                }
                return true;
            }
            catch
            {
                return false;
            }
        }

        public string ReadLine()
        {
            try
            {
                string receive = sp.ReadLine();
                return receive;
            }
            catch (Exception ex)
            {
                return "";
            }
        }

        public bool WriteLine(string barcode)
        {
            sp.WriteLine(barcode);
            return true;
        }
    }

客户端代码：

 public partial class Form1 : Form
    {
        CComController com;
        public Form1()
        {
            InitializeComponent();




            com = new CComController();
            com.OpenCom("COM1", 115200, 8, 1, 0);
        }


        public void SendBarcode()
        {



        }


        private void btnSend_Click(object sender, EventArgs e)
        {
            string barcode = txtBarcode.Text;
            com.WriteLine(barcode);
        }
    }

服务端：

namespace ComServer
{
    public partial class Form1 : Form
    {
        CComController comController;
        CKeyController keyController;
        public Form1()
        {
            InitializeComponent();
            //textBox1.Focus();


            comController = new CComController();
            comController.OpenCom("COM1", 115200, 8, 1, 0);

            keyController = new CKeyController();
            keyController.InitKey();
            Thread readThread = new Thread(new ThreadStart(ThreadReadBarcode));
            readThread.Start();
        }


        public void ThreadReadBarcode()
        {
            while (true)
            {
                string barcode = comController.ReadLine();
                if (barcode != "" && barcode != null)
                {
                    keyController.SendKeyByMessage(barcode);
                }


                Thread.Sleep(200);
            }
        }
    }
}

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