private void SavePDFMethod(Action <bool> callback)
 {
     try
     {
         Device.BeginInvokeOnMainThread(() =>
         {
             using (var printMgr = (PrintManager)ctx.GetSystemService(Context.PrintService))
             {
                 var wrapper = new PrintDocumentAdapterWrapper(NativeView.CreatePrintDocumentAdapter($"{cvw.FileName}"), () =>
                 {
                     callback?.Invoke(true);
                 });
                 job = printMgr.Print("CoreWebView PrintJob", wrapper, null);
             }
         });
     }
     catch (Exception ex)
     {
         cvw.PDFException = ex;
         callback?.Invoke(false);
     }
 }