Access to the port 'COM5' is denied

问题

I get the following error message Access to the port 'COM5' is denied. when running the method below from my form. I have tried entering the right baud rate of 9600 from the port setting of my device manager. I have also tried accessing the devices through Portmon but there is a bug that prevents me from being connected. Any alternative to solve this problem?

      //Fields
    List<string> myReceivedLines = new List<string>();

    //subscriber method for the port.DataReceived Event
    private void DataReceivedHandler(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
    {
        SerialPort sp = (SerialPort)sender;
        while (sp.BytesToRead > 0)
        {
            try
            {
                myReceivedLines.Add(sp.ReadLine());
            }
            catch (TimeoutException)
            {
                break;
            }
        }
    }

    protected override void SolveInstance(IGH_DataAccess DA)
    {

        string selectedportname = default(string);
        DA.GetData(1, ref selectedportname);
        int selectedbaudrate = default(int);
        DA.GetData(2, ref selectedbaudrate);
        bool connecttodevice = default(bool);
        DA.GetData(3, ref connecttodevice);

        port.DtrEnable = true;   //enables the Data Terminal Ready (DTR) signal during serial communication (Handshaking)
        port.Open();             //Open the port
        if (!(port.IsOpen == true)) port.Open();


        if (connecttodevice == true)
        {
            port.DataReceived += new SerialDataReceivedEventHandler(DataReceivedHandler);
            DA.SetDataList(0, myReceivedLines);
        }

回答1:

You need to wrap the use of SerialPort in a using statement or implement IDisposable

// Dispose() calls Dispose(true)
public void Dispose()
{
    Dispose(true);
    GC.SuppressFinalize(this);
}

// The bulk of the clean-up code is implemented in Dispose(bool)
protected virtual void Dispose(bool disposing)
{
    if (disposing)
    {
        // free managed resources
        if (_serialPort != null)
        {
            _serialPort.Dispose();
            _serialPort = null;
        }
    }
    // free native resources if there are any.
}

来源：https://stackoverflow.com/questions/12657479/access-to-the-port-com5-is-denied

标签

serial-port