private async void BtnCameraQrCode_Clicked(object sender, EventArgs e) { ZXing.Mobile.MobileBarcodeScanner scanner = new ZXing.Mobile.MobileBarcodeScanner { FlashButtonText = "Flash", TopText = "Cima", BottomText = "Baixo" }; var result = await scanner.Scan(); if (result != null) { string codigoQrCode = result.Text; if (!codigoQrCode.StartsWith("http")) { await DisplayAlert("QrCode", "QrCode Inválido", "Ok"); } viewModel.AtualizaQrCode(codigoQrCode); } }