Getting an IEnumerable from a port.DataReceived Event and its subscriber method?

Question

I am trying to read data received from a device but I get the following error with line DA.SetDataList(0, port.DataReceived);:

The best overloaded method match for Grasshopper.Kernel.IGH_DataAccess.SetDataList(int,System.Collections.IEnumerable) has some valid arguments.

The SetDataList(int32, IEnumerable) is part of the Grasshopper Kernel. port.DataReceived is an event and therefore not a valid IEnumerable argument, it stores a list of data in an output parameter during GH_Component.SolveInstance(). I have set up a subscriber method portdatareceived which gives me strings. How can I get an IEnumerable from this method?

  SerialPort port;

   protected override void SolveInstance(IGH_DataAccess DA)
    {
    string gcode = default(string);
    DA.GetData(0, ref gcode);

    port = new SerialPort(selectedportname, selectedbaudrate, Parity.None, 8, StopBits.One); 
    port.DtrEnable = true;   
    port.Open();            
    port.DataReceived += this.portdatareceived;

    if (gcode == null)
    {
        AddRuntimeMessage(GH_RuntimeMessageLevel.Warning, "Specify a valid GCode");
        return;
    }
    else
    {
        DA.SetDataList(0, port.DataReceived);
    }    
    }

  private void portdatareceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
    {
       string line = port.ReadExisting();
    }

Answer 1

Making the line variable in the subscriber method a field and accessing it from the SetDataList method works:

SerialPort port;
string myReceivedLines;

   protected override void SolveInstance(IGH_DataAccess DA)
  {

    string gcode = default(string);
    DA.GetData(0, ref gcode);

    port = new SerialPort(selectedportname, selectedbaudrate, Parity.None, 8, StopBits.One);
    port.DtrEnable = true;   
    port.Open();            
    port.DataReceived += this.portdatareceived;

    if (gcode == null)
    {
        AddRuntimeMessage(GH_RuntimeMessageLevel.Warning, "Specify a valid GCode");
        return;
    }
    else
    {
        DA.SetDataList(0,  myReceivedLines);
        port.WriteLine(gcode);
    }    
              }

    private void portdatareceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
    {
        myReceivedLines = port.ReadExisting();
    } 

Answer 2

I don't know anything about GrassHopper, so this could be completely wrong.

Because port.DataReceived is an event I don't think you really want it as an IEnumerable. Instead what you want is to wait for the event to be raised, and then perhaps the arguments passed in to this event will contain the data for your datalist.

So find the definition of this.portdatareceived and try to convert one of its arguments into an IEnumberable. The code might look vaguely something like:

private void DataReceived(object sender, EventArgs e)
{
    IEnumerable hopefullyThisIsYourData = (IEnumerable)e;
    DA.SetDataList(0, hopefullyThisIsYourData);  
}

You could add a break point here to find out what is in e, and fix the code accordingly.

Answer 3

With this code:

port.DataReceived += this.portdatareceived;

Seem port.DataReceived is an event, whereas, your method needs IEnumerable:

IGH_DataAccess.SetDataList(int,System.Collections.IEnumerable)

To solve this, you need to call this method inside portdatareceived by getting correct data from event argument.