Serial Port ReadLine vs ReadExisting 或如何正确地从串口读取数据

问题描述

我正在从串口读取数据.数据超出规模.我现在正在使用 Readline() 并且即使在我删除 DiscardInBuffer() 之后也会删除数据.

I am reading data from serial port. The data comes off the scale. I am now using Readline() and getting data dropped even after I removed DiscardInBuffer().

从串口读取数据的正确方法是什么?网上的例子太少了，我觉得这就像一个没有人想出来的圣杯.

What is the proper way to read the data from the serial port? There are so few examples online that I feel it's like some holy grail that no one has figured out.

C#、WinCE 5.0、HP 瘦客户端、Compact 框架 2.0

C#, WinCE 5.0, HP thin client, Compact framework 2.0

 private void WeighSample()
    {
        this._processingDone = false;
        this._workerThread = new Thread(CaptureWeight);
        this._workerThread.IsBackground = true;
        this._workerThread.Start();
    } //end of WeighSample()


    private void CaptureWeight()
    {
         globalCounter++;
         string value = "";


          while (!this._processingDone)
          {
              try
              {

                 value = this._sp.ReadLine();

                  if (value != "")
                  {
                      if (value == "ES")
                      {
                          _sp.DiscardInBuffer();
                          value = "";
                      }
                      else
                      {
                          this.Invoke(this.OnDataAcquiredEvent, new object[] { value });
                      }
                  }
              }
              catch (TimeoutException)
              {
                  //catch it but do nothing
              }
              catch
              {
                  //reset the port here?
                  MessageBox.Show("some other than timeout exception thrown while reading serial port");
              }
          }


    } //end of CaptureWeight()

关于我的应用程序需要注意的一点是，当光标跳到文本框时，我会启动线程 (weighSample).原因是重量也可以手动输入(部分要求).所以我事先不知道用户是要按天平上的 PRINT 还是输入重量.无论哪种情况，在获取数据后，我都会退出工作线程.另外，请注意我没有使用串行端口事件 DataReceived，因为我被告知它不可靠.

One thing to note about my application is that I start the thread (weighSample) when the cursor jumps onto the textbox. The reason to this is that the weight can also be typed in manually (part of the requirements). So I don't know in advance whether a user is going to press PRINT on the balance or type the weight. In either case after the data is acquired, I exit the worker thread. Also, note that I am not using serial port event DataReceived, since I have been told it's not reliable.

这是我第一次使用串口.

This is my first experience with serial ports.

推荐答案

我从来没有在 ReadLine 工作时遇到过运气.只需在数据可用时读取本地缓冲区，然后使用单独的线程扫描数据并自行查找换行符.

I have never had luck with ReadLine working. Just do a Read into a local buffer whenever data is available and then use a separate thread to scan the data and find line breaks yourself.

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