Question

我有一个FTDI串口，我必须在串口写一些东西才能开始读22字节我有一个非常奇怪的问题。我读的这个数据太慢了

我不知道我的问题是什么

这是我的代码：`

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }
    int count;

    private void button1_Click(object sender, EventArgs e)
    {
       // serialPort1.Open();

       // serialPort1.Write(Convert.ToString(0x02));  //here we converted the same method to convert hex to string to be send using serial port
        //textBox3.Text = (Convert.ToString(0x02));   //here we will see what will be sent with serial port
        serialPort1.Write(textBox5.Text);
     //   serialPort1.Close();
    }

    private void button2_Click(object sender, EventArgs e)
    {
        serialPort1.PortName = textBox1.Text;
        serialPort1.BaudRate = Convert.ToInt32(textBox2.Text);


    }

    // int rs;
    byte[] rs=new byte[22];

    private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
    {
        try
        {
           // rs = serialPort1.ReadByte();
            serialPort1.Read(rs, 0, 22);
            this.Invoke(new EventHandler(type));

        }
        catch (System.TimeoutException) { }
    }
    void type(object s,EventArgs e)
    {
        textBox4.Text = rs.ToString(); //this method should view what is being recieve by the serial port :)

        label4.Text =rs[0].ToString();
        label5.Text = "" + rs[1];
        label6.Text = "" + rs[2];
        label7.Text = "" + rs[3];
        label8.Text = "" + rs[4];
        label9.Text = "" + rs[5];
        label10.Text = "" + rs[6];
        label11.Text = "" + rs[7];
        label12.Text = "" + rs[8];
        label13.Text = "" + rs[9];
        label14.Text = "" + rs[10];
        label15.Text = "" + rs[11];
        label16.Text = "" + rs[12];
        label17.Text = "" + rs[13];
        label18.Text = "" + rs[14];
        label19.Text = "" + rs[15];
        label20.Text = "" + rs[16];
        label21.Text = "" + rs[17];
        label22.Text = "" + rs[18];
        label23.Text = "" + rs[19];
        label24.Text = "" + rs[20];
        label25.Text = "" + rs[21];

        count++;

    }

    private void button3_Click(object sender, EventArgs e)
    {
        serialPort1.Open();
        // start timer to count

        serialPort1.Write("?");
        serialPort1.Write("5");
        serialPort1.Write("1");
        serialPort1.Write("&");

        timer1.Start();

    }

    private void button4_Click(object sender, EventArgs e)
    {
        serialPort1.Close();

    }

    private void timer1_Tick(object sender, EventArgs e)
    {
        // after 1000 mili second this timer will do the following 
        timer1.Stop();

        textBox6.Text = count.ToString();
        count = 0; // re initialize the count variable :)
        timer1.Start();
    }
}

}

当我使用serialport1-readExisting();时，时间是真的（我想要的是（5/5）），但数据是字符串，我的数据是整数，所以没用。

我确定我的问题与使用serialport1.Read(rs,0,22)有关但我真的不知道我该做什么

如果有人可以帮助我，我会感激不尽。

Answer 1

        serialPort1.Read(rs, 0, 22);

您不能忽略Read（）的返回值，它不会是22.如果您立即调用，也不能忽略e.EventType。你不应该这样做，在你做之前收集整个回复。您只需要另一个变量来跟踪您收到的字节数。修正：

    byte[] rs = new byte[22];
    int rsCnt = 0;

    private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e) {
        if (e.EventType != SerialData.Chars) return;
        rsCnt += serialPort1.Read(rs, rsCnt, 22 - rsCnt);
        if (rsCnt == 22) {
            this.BeginInvoke(new Action(() => type(rs)));
            rs = new byte[22];
            rsCnt = 0;
        }
    }

    private void type(byte[] data) {
        // etc...
    }

检查e.EventType可以避免TimeoutException，当您将ReadTimeout设置为0时，您将不需要它。使用BeginInvoke（）而不是Invoke（）可以在调用serialPort1.Close（）方法时避免死锁。当port（）忙于处理数据而端口继续接收数据时，重新创建缓冲区可以避免线程竞争。

从c＃中的FTDI串口读取22个字节太慢了

1 个答案: