Q:

A local variable named 'port' cannot be declared

I am trying to build an Arduino project to measure CPU and GPU temps through Open Hardware Monitor and now I have problem in C# application. 
It gives this error on line 45:

A local variable named 'port' cannot be declared in this scope
  because it would give a different meaning to 'port', which is already
  used in a 'parent or current' scope to denote something else

Can I get some help? Thank you very much! 
private void Init()
{
    try
    {
        notifyIcon1.Visible = false;
        port.Parity = Parity.None;
        port.StopBits = StopBits.One;
        port.DataBits = 8;
        port.Handshake = Handshake.None;
        port.RtsEnable = true;
        string[] ports = SerialPort.GetPortNames();
45      foreach (string port in ports)
        {
            comboBox1.Items.Add(port);
        }
        port.BaudRate = 9600;
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}

A:

You have a variable named port in your code already. So it doesn't allow you to declare it again in your foreach loop. Change it's name to something else:
foreach (string port2 in ports)
{
    comboBox1.Items.Add(port2);
}

