Zxing.Net.Mobile Forms and MVVM Xaml Not Scanning - mvvm

Question

New to Xamarin development! Using Visual Studio 2017 and all the latest installs and updates for my dev environment.
I have my app "shell" working in that it will run, navigate, crud to local db, and sync to rest services. So, the base of my app is sound. I am trying to integrate the ZXing barcode scanner into my app. Most of what help I can find relates to raw forms or code behind xaml. I am using views and view models and I don't know how to translate the information I am finding to this model.
I currently have the xaml view showing the "camera viewer" when a button is clicked so I can see a barcode using the camera. However, there is no "red line" in the camera view and subsequently, there are no events being fired to let me know what is going on. I really am confused as I am so new to Xamarin. I don't know where to start.
XAML View page
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:prism="clr-namespace:Prism.Mvvm;assembly=Prism.Forms"
xmlns:fe="clr-namespace:FreshEssentials;assembly=FreshEssentials"
xmlns:forms="clr-namespace:ZXing.Net.Mobile.Forms;assembly=ZXing.Net.Mobile.Forms"
prism:ViewModelLocator.AutowireViewModel="True"
x:Class="Views.InventoryPage1"
Title="Inventory Page">
<StackLayout Spacing="5" Padding="10,10,10,0">
<!--<fe:BindablePicker ItemsSource="{Binding Areas}" SelectedItem="{Binding SelectedArea}" DisplayProperty="AreaName" Title="Select Your Area" />
<fe:BindablePicker ItemsSource="{Binding Reasons}" SelectedItem="{Binding SelectedReason}"
DisplayProperty="Description" Title="Select a Reason" />
<Label Text="Scan"/>
<Entry Text="{Binding Barcode}"/>
<Label Text="Quantity"/>
<Entry Text="{Binding Quantity}"/>
<Button Text="Save" Style="{StaticResource Button_Primary}" Command="{Binding SaveCommand}" />-->
<forms:ZXingScannerView WidthRequest="100" HeightRequest="100" IsScanning="{Binding IsScanning}" IsAnalyzing="{Binding IsAnalyzing}" Result="{Binding Result, Mode=TwoWay}" ScanResultCommand="{Binding QRScanResultCommand}" ></forms:ZXingScannerView>
</StackLayout>
</ContentPage>
ViewModel
public class InventoryPage1ViewModel : BindableBase, INavigationAware
{
private readonly IPageDialogService _pageDialogService;
private bool _isAnalyzing = true;
private bool _isScanning = true;
public ZXing.Result Result { get; set; }
public List<Area> Areas { get; private set; }
public Area SelectedArea { get; set; }
public List<Reason> Reasons { get; private set; }
public Reason SelectedReason { get; set; }
public int Quantity { get; set; }
public string Barcode { get; set; }
public DelegateCommand SaveCommand => new DelegateCommand(PerformSave);
public DelegateCommand QRScanResultCommand => new DelegateCommand(QRCommand);
private readonly IAreaService _areaService;
private readonly IScanService _scanService;
private readonly IReasonService _reasonService;
public InventoryPage1ViewModel(IAreaService areaService, IScanService scanService, IReasonService reasonService, IPageDialogService pageDialogService)
{
_pageDialogService = pageDialogService;
_reasonService = reasonService;
_scanService = scanService;
_areaService = areaService;
Areas = _areaService.GetAll();
Reasons = _reasonService.GetAll();
}
public bool IsScanning
{
get
{
return _isScanning;
}
set
{
_isScanning = value;
RaisePropertyChanged();
}
}
public bool IsAnalyzing
{
get
{
return _isAnalyzing;
}
set
{
_isAnalyzing = value;
RaisePropertyChanged();
}
}
private void QRCommand()
{
int x = 1;
}
private async void PerformSave()
{
var scan = new Scan()
{
AreaId = SelectedArea.Id,
InsertDateTime = DateTime.Now,
ReasonId = SelectedReason.Id,
ScanItem = Barcode,
ScanQty = Quantity,
IsUploaded = false
};
// Save it to the DB here.
var retVal = _scanService.Insert(scan);
if (retVal)
{
await _pageDialogService.DisplayAlertAsync("Saved", "Scan saved successfully.", "OK");
}
else
{
// TODO: Inform the user something went wrong.
}
}
int _index;
public int SelectIndex
{
get
{
return _index;
}
set
{
_index = value;
RaisePropertyChanged("SelectIndex");
}
}
public void OnNavigatedFrom(NavigationParameters parameters)
{
}
public void OnNavigatedTo(NavigationParameters parameters)
{
}
public void OnNavigatingTo(NavigationParameters parameters)
{
}
}
MainActivity
public class MainActivity :
global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
protected override void OnCreate(Bundle bundle)
{
TabLayoutResource = Resource.Layout.tabs;
ToolbarResource = Resource.Layout.toolbar;
base.OnCreate(bundle);
global::Xamarin.Forms.Forms.Init(this, bundle);
ZXing.Net.Mobile.Forms.Android.Platform.Init();
LoadApplication(new App(new AndroidInitializer()));
}
public override void OnRequestPermissionsResult(int requestCode, string[] permissions, Permission[] grantResults)
{
ZXing.Net.Mobile.Android.PermissionsHandler.OnRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
public class AndroidInitializer : IPlatformInitializer
{
public void RegisterTypes(IUnityContainer container)
{
container.RegisterType<IConnectionFactory, ConnectionFactory>();
}
}
UPDATE
I have a working view model now thanks to #Krzysztof over at Xamarin.Forms.
New ViewModel
public class InventoryPage1ViewModel : BindableBase, INavigationAware
{
private readonly IPageDialogService _pageDialogService;
public List<Area> Areas { get; private set; }
public Area SelectedArea { get; set; }
public List<Reason> Reasons { get; private set; }
public Reason SelectedReason { get; set; }
public int Quantity { get; set; }
public DelegateCommand SaveCommand => new DelegateCommand(PerformSave);
private readonly IAreaService _areaService;
private readonly IScanService _scanService;
private readonly IReasonService _reasonService;
public InventoryPage1ViewModel(IAreaService areaService, IScanService scanService, IReasonService reasonService, IPageDialogService pageDialogService)
{
_pageDialogService = pageDialogService;
_reasonService = reasonService;
_scanService = scanService;
_areaService = areaService;
Areas = _areaService.GetAll();
Reasons = _reasonService.GetAll();
}
public ZXing.Result Result { get; set; }
private string barcode = string.Empty;
public string Barcode
{
get
{
return barcode;
}
set
{
barcode = value;
RaisePropertyChanged();
}
}
private bool isAnalyzing = true;
public bool IsAnalyzing
{
get { return this.isAnalyzing; }
set
{
if (!bool.Equals(this.isAnalyzing, value))
{
this.isAnalyzing = value;
RaisePropertyChanged(nameof(IsAnalyzing));
}
}
}
private bool isScanning = true;
public bool IsScanning
{
get { return this.isScanning; }
set
{
if (!bool.Equals(this.isScanning, value))
{
this.isScanning = value;
RaisePropertyChanged(nameof(IsScanning));
}
}
}
public Command QRScanResultCommand
{
get
{
return new Command(() =>
{
IsAnalyzing = false;
IsScanning = false;
Device.BeginInvokeOnMainThread(async () =>
{
Barcode = Result.Text;
await _pageDialogService.DisplayAlertAsync("Scanned Item", Result.Text, "Ok");
});
IsAnalyzing = true;
IsScanning = true;
});
}
}
private async void PerformSave()
{
var scan = new Scan()
{
AreaId = SelectedArea.Id,
InsertDateTime = DateTime.Now,
ReasonId = SelectedReason.Id,
ScanItem = Barcode,
ScanQty = Quantity,
IsUploaded = false
};
// Save it to the DB here.
var retVal = _scanService.Insert(scan);
if (retVal)
{
await _pageDialogService.DisplayAlertAsync("Saved", "Scan saved successfully.", "OK");
}
else
{
// TODO: Inform the user something went wrong.
}
}
public void OnNavigatedFrom(NavigationParameters parameters)
{
}
public void OnNavigatedTo(NavigationParameters parameters)
{
}
public void OnNavigatingTo(NavigationParameters parameters)
{
}
}