private void SearchForPortAndAddOrRemove(object sender, EventArgs e)
{
List <string> portlist = SerialPort.GetPortNames().ToList();
var oldports = PortList.Except(portlist).ToList();
var newports = portlist.Except(PortList).ToList();
if (oldports.Count == 0 && newports.Count == 0)
{
return;
}
PortList = portlist;
OnPropertyChanged(nameof(PortList));
}