自动调整C＃中的COM串行端口

Question

I've got Arduino Nano controlling a DC motor connected to my PC and controlled over C#. The only problem is that it works on my computer at the moment, and if I connect it to another PC it won't work unless it uses the same serial port. That's why I want the COM port to "set itself". Is it possible to do? If not, I wanted to make another Form just for entering the number of COM port, but I want to avoid that if possible. Thank you in advance. This is my code:

public partial class Form1 : Form
{
    String s = "0";
    string brojPorta = "COM5";
    int vrijednost = 0;
    System.IO.Ports.SerialPort serialPort1;
    public Form1()
    {
        InitializeComponent();
        System.ComponentModel.IContainer components =
    new System.ComponentModel.Container();
        serialPort1 = new System.IO.Ports.SerialPort(components);
        serialPort1.PortName = brojPorta;
        serialPort1.BaudRate = 9600;
        serialPort1.Open();
    }
    private void Form1_FormClosing(object sender, FormClosingEventArgs e)
    {
        if (serialPort1.IsOpen) serialPort1.Close();
    }

    private void Klizac1_Scroll(object sender, ScrollEventArgs e)
    {
        vrijednost = Klizac1.Value;
        s = (vrijednost * 10.24).ToString();
        serialPort1.Write(s + '\n');
        label1.Text = ((vrijednost-50)*2).ToString()+"%";
    }

    private void btn_Zaustavi_Click(object sender, EventArgs e)
    {
        Klizac1.Value = 50;
        label1.Text = "0";
        s = (Klizac1.Value * 10.24).ToString();
        serialPort1.Write(s + '\n');
    }
}

Answer 1

First you would have to enumerate all the ports. See this question: How to find available COM ports?

Then you would have to attempt to connect on each port with a timeout until you find it.

The more prudent scenario is to enumerate the available ports in a drop down list and have the user select the port it's connected to.

Answer 2

There could be some pitfalls here but this example appears to work:

/*Use the WMI to search for the Arduino device on a serial port driver
and assign the serial port to the device*/

ManagementObjectSearcher SerialPortSearcher =
    new ManagementObjectSearcher(
    "root\\CIMV2",
    "SELECT * FROM Win32_SerialPort");

foreach (ManagementObject SerialPortObject in SerialPortSearcher.Get())
{
    if (SerialPortObject["Description"].ToString() == "Arduino Mega 2560")
    {
        SerialPort _serialPort =
            new SerialPort(SerialPortObject["DeviceID"].ToString());
        break;
    }
}