通过串行连接从智能卡读卡器接收数据（C＃）

3 回答

• 0

  您需要实际读取 serialPort_DataReceived 中的数据 . 你're not doing anything here. Also: There'是 button1_Click 事件和 button1_Click_1 事件 . button1 正在调用哪一个？如果未调用第一个，则根本不打开串行端口 .

  另请注意： DataReceived 事件在其自己的线程中调用，因此在更新UI之前，您需要使用 this.Invoke （WinForms）或 this.Dispatcher.Invoke （WPF）更改为UI线程 .

  回复于 2024-05-06T02:09:21+08:00
• 0

  我在这里看到两个问题：

  • 您没有从端口读取数据..

  • 我认为你将在更新表单时遇到问题，因为它将从另一个线程调用 .

  为了让你去，你可以添加一个计时器，并在计时器滴答事件中读取数据，如果端口有任何数据：

  private void timer1_Tick(object sender, EventArgs e)
      {
          if (s1.BytesToRead > 0)
          {
              //write text to text box
  
              //e.g. maybe as a start try
              txtDataReceived.Text += s1.ReadExisting();
          }
      }
  

  关于从另一个线程更新表单的另一个问题是：

  How to update the GUI from another thread in C#?

  回复于 2024-05-06T02:09:21+08:00
• 0

  update

  运行 updateTextBox() manualy（将其添加到ButtonClick EventHandler）

  public void updateTextBox()
      {
          byte[] buffer = new byte[255];
  
          serialPort.Read(buffer, 0, 4); 
          var i = 0; //Press F9 here, it will put a breakpoint here
      }
  

  然后运行你的应用程序，并在断点停止后检查缓冲区是否为空？

  Update2 好的，试试这段代码吧，阅读我的评论 .

  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.IO.Ports;
  using System.IO;
  
  namespace mycard
  {
      public partial class Form1 : Form
      {
          byte[] memo = new byte[256];
          byte[] buffer = new byte[255];
  
          //private SerialPort serialPort = new SerialPort();
          //We don't need this object. We never configure it, it's not the 
          //same object which you use to write 'eject bytes'!
          public Form1()
          {
              InitializeComponent();
          }
  
          private void Form1_Load(object sender, EventArgs e)
          {
             //subscribe on data received event here. IMPORTANT: we 'listen' s1 object here!
              s1.DataReceived += 
                  new SerialDataReceivedEventHandler(serialPort_DataReceived);
          }
  
          //open port
          private void button1_Click(object sender, EventArgs e)
          {
              if (s1.IsOpen)
              {
                  s1.Close();
              }
              s1.Open();
          }
  
          //Eject order which is working fine
          private void button1_Click_1(object sender, EventArgs e)
          {
              byte[] data= new byte[4];
  
              memo[0]=0x60;
              memo[1]=0x00;
              memo[2]=0x02;
              memo[3]=0x43;
              memo[4]=0x31; //32
              memo[5]=0x10; //13
  
              s1.Write(memo,0,6);
          }
  
          //close port
          private void button2_Click(object sender, EventArgs e)
          {
              s1.Close();
          }
  
          private void button3_Click(object sender, EventArgs e)
          {
              txtDataReceived.Text = "\r\n";
          }
  
          public void updateTextBox()
          {
              byte[] buffer = new byte[255];
  
              //we must read from s1, not from serealPort!!!
              s1.Read(buffer, 0, 4);
              txtDataReceived.Text = (buffer[0].ToString() + Environment.NewLine 
                  + buffer[1].ToString() + Environment.NewLine 
                  + buffer[2].ToString() + Environment.NewLine 
                  + buffer[3].ToString() + Environment.NewLine);
          }
  
          //data received, let's read it!
          private void serialPort_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
          {
            updateTextBox(); 
          }
      }
  }
  

  your problem 您有一个 SerialPort 类的实例 . 实例名称为 s1 . 您已配置它，但您尝试从新的 serialPort 对象中读取数据 . 显然那里没有数据 .

  Serial ports details

  回复于 2024-05-06T02:09:21+08:00