private void DiscoveryHandler_OnFoundPrinter(object sender, IDiscoveredPrinter discoveredPrinter)
 {
     System.Diagnostics.Debug.WriteLine("Found Printer:" + discoveredPrinter.ToString());
     Device.BeginInvokeOnMainThread(() =>
     {
         if (!PrinterList.Contains(discoveredPrinter))
         {
             PrinterList.Add(discoveredPrinter);
         }
     });
 }