Question

我正在尝试使用虚拟串行端口程序通过串行通信发送和接收数据。但这是问题... 假设A是发送数据，B是接收数据。

当A向B发送数据时，B两次接收数据（serialport_datareceived事件发生两次！）。

每次B关闭串行端口并再次打开时，serialport_datareceived事件都会增加。

我不知道为什么会这样。

A(transmit)
BaudRate = 9600
Parity = None
DataBits = 8
StopBits = 1

    public transmit()
    {
        InitializeComponent();
        foreach (String s in System.IO.Ports.SerialPort.GetPortNames())
        {
            cBoxPort.Items.Add(s);          
        }
    }
    private void CBoxBaudRate_SelectedIndexChanged(object sender, EventArgs e)
    {
        serialPort1.BaudRate = Convert.ToInt32(cBoxBaudRate.Text);                          
    }
    private void CBoxStopBits_SelectedIndexChanged(object sender, EventArgs e)
    {
        serialPort1.StopBits = (StopBits)Enum.Parse(typeof(StopBits), cBoxStopBit.Text);   
    }
    private void CBoxDataBits_SelectedIndexChanged(object sender, EventArgs e)
    {
        serialPort1.DataBits = Convert.ToInt32(cBoxDataBits.Text);                          
    }
    private void CBoxParityBits_SelectedIndexChanged(object sender, EventArgs e)
    {
        serialPort1.Parity = (Parity)Enum.Parse(typeof(Parity), cBoxParity.Text);           
    }

    private void btnConnect_Click(object sender, EventArgs e)
    {
        try
        {
            serialPort1.PortName = cBoxPort.Text;
            serialPort1.BaudRate = Convert.ToInt32(cBoxBaudRate.Text);
            serialPort1.DataBits = Convert.ToInt32(cBoxDataBits.Text);
            serialPort1.StopBits = (StopBits)Enum.Parse(typeof(StopBits), cBoxStopBit.Text);
            serialPort1.Parity = (Parity)Enum.Parse(typeof(Parity), cBoxParity.Text);
            serialPort1.DataReceived += new SerialDataReceivedEventHandler(serialPort1_DataReceived);
            serialPort1.Open();

            txtReceive.AppendText("Connected\n");   
            btnConnect.Enabled = false;             
            btnClose.Enabled = true;
            btnSend.Enabled = true;
        }

        catch (Exception ex)
        {
            return;
        }
    }
    private void btnClose_Click(object sender, EventArgs e)
    {
        if (serialPort1.IsOpen)
        {
            serialPort1.Close();                        
            btnClose.Enabled = false;
            btnConnect.Enabled = true;
            btnSend.Enabled = false;
            txtReceive.AppendText("Disconnected\n");  
        }
    }

    private void btnSend_Click(object sender, EventArgs e)
    {
        byte[] bytesend = { 0x00 };
        Debug.WriteLine("111");
        serialPort1.Write(bytesend, 0, bytesend.Length);
    }

    private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
    {
        Debug.WriteLine("444");
    }

}

B（接收）

    byte[] bytesend;

    //Initial Conditions(SerialPort)
    private void receive_Load(object sender, EventArgs e)
    {
        cBoxBaudRate.SelectedIndex = 0;     //BaudRate = 9600
        cBoxParity.SelectedIndex = 0;       //Parity = None
        cBoxDataBits.SelectedIndex = 0;     //DataBits = 8
        cBoxStopBit.SelectedIndex = 0;      //StopBits = 1
        cBoxPort.SelectedIndex = 1;         

        btnConnect.Enabled = true;
        btnClose.Enabled = false;
    }

    //Show usable CommPort
    public receive()
    {
        InitializeComponent();
        foreach (String s in System.IO.Ports.SerialPort.GetPortNames())
        {
            cBoxPort.Items.Add(s);
        }
    }

    //Connection
    private void btnConnect_Click(object sender, EventArgs e)
    {
        serialPort1.PortName = cBoxPort.Text;
        serialPort1.BaudRate = Convert.ToInt32(cBoxBaudRate.Text);
        serialPort1.DataBits = Convert.ToInt32(cBoxDataBits.Text);
        serialPort1.StopBits = (StopBits)Enum.Parse(typeof(StopBits), cBoxStopBit.Text);
        serialPort1.Parity = (Parity)Enum.Parse(typeof(Parity), cBoxParity.Text);
        serialPort1.DataReceived += new SerialDataReceivedEventHandler(serialPort1_DataReceived);
        serialPort1.Open();

        btnConnect.Enabled = false;
        btnClose.Enabled = true;
    }
    private void btnClose_Click(object sender, EventArgs e)
    {
        if (serialPort1.IsOpen)
        {
            serialPort1.Close();
            btnClose.Enabled = false;
            btnConnect.Enabled = true;
        }
    }

    private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
    {
        Debug.WriteLine("222");
    }

当我调试此代码时，输出表示111 222222。当我按下关闭并连接按钮时，输出表示111 222 222 222。

Answer 1

每次B关闭串口并再次打开时， serialport_datareceived事件发生增加。

对，因为就像我说的那样，您应该只连接一次DataReceived事件。每次您单击按钮时，都会添加另一个处理程序，从而导致单次接收多次触发。这与多线程无关。将连接处理程序的线路从按钮click事件移到Load事件：

private void transmit_Load(object sender, EventArgs e)
{
    serialPort1.DataReceived += new SerialDataReceivedEventHandler(serialPort1_DataReceived); // now it only gets called once
    // ... other existing code ...
}


private void btnConnect_Click(object sender, EventArgs e)
{
    try
    {
        serialPort1.PortName = cBoxPort.Text;
        serialPort1.BaudRate = Convert.ToInt32(cBoxBaudRate.Text);
        serialPort1.DataBits = Convert.ToInt32(cBoxDataBits.Text);
        serialPort1.StopBits = (StopBits)Enum.Parse(typeof(StopBits), cBoxStopBit.Text);
        serialPort1.Parity = (Parity)Enum.Parse(typeof(Parity), cBoxParity.Text);
        // serialPort1.DataReceived += new SerialDataReceivedEventHandler(serialPort1_DataReceived);  // remove this line
        serialPort1.Open();

        txtReceive.AppendText("Connected\n");   
        btnConnect.Enabled = false;             
        btnClose.Enabled = true;
        btnSend.Enabled = true;
    }

    catch (Exception ex)
    {
        return;
    }
}

您还需要在接收表单中做同样的事情。

接收数据时，[serialport_datareceived]事件会多次发生（使用虚拟串行端口）

1 个答案: