service is returning null wpf mvvm

Question

I'm trying to bind data in my data context but service is returning null. I'm using ninject as DI. I'm sharing my app.xaml.cs code. Please guide me.

public partial class App
{
    private IKernel container;

    protected override void OnStartup(StartupEventArgs e)
    {
        base.OnStartup(e);
        AutoMapperConfig.RegisterMappings();
        ConfigureContainer();
        ComposeObjects();
        Current.MainWindow.Show();
    }

    private void ConfigureContainer()
    {
        this.container = new StandardKernel();
        container.Bind(typeof(IAppServiceBase<>)).To(typeof(AppServiceBase<>));
        container.Bind<IJvDetailAppService>().To<JvDetailAppService>().InSingletonScope();
        container.Bind<IJvMasterAppService>().To<JvMasterAppService>().InSingletonScope();
        container.Bind<IJvDimensionAppService>().To<JvDimensionAppService>().InSingletonScope();
        container.Bind(typeof(IServiceBase<>)).To(typeof(ServiceBase<>));
        container.Bind<IJvDetailService>().To<JvDetailService>();
        container.Bind<IJvMasterService>().To<JvMasterService>();
        container.Bind<IJvDimensionService>().To<JvDimensionService>();

        container.Bind(typeof(IRepositoryBase<>)).To(typeof(RepositoryBase<>));
        container.Bind<IJvDetailRepository>().To<JvDetailRepository>();
        container.Bind<IJvMasterRepository>().To<JvMasterRepository>();
        container.Bind<IJvDimensionRepository>().To<JvDimensionRepository>();
    }

    private void ComposeObjects()
    {          
        Current.MainWindow = this.container.Get<MainWindow>();
        Current.MainWindow.Title = "JustApp";
    }
}

MainWindowViewModel

public class MainWindowViewModel : ViewModelBase
{
    private readonly BackgroundWorker _worker = new BackgroundWorker();

    private ObservableCollection<JvDetailViewModelBase> _jvDetailMenu;
    private readonly IJvDetailAppService _jvDetailAppService;

    public ObservableCollection<JvDetailViewModelBase> JvDetailMenu
    {
        get { return this._jvDetailMenu; }
        set
        {
            _jvDetailMenu = value;
            RaisedPropertyChanged("JvDetailMenu");
        }
    }

    public MainWindowViewModel()
    {
        _worker.DoWork += worker_DoWork;
        _worker.RunWorkerCompleted += worker_RunWorkerCompleted;
        _worker.RunWorkerAsync();

    }

    readonly ObservableCollection<JvDetailViewModelBase> _tempProductMenu = new ObservableCollection<JvDetailViewModelBase>();
    private void worker_DoWork(object sender, DoWorkEventArgs e)
    {
      _tempProductMenu.Add(new ModifyJvDetailViewModel(_jvDetailAppService));
    }

    private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        if (_tempProductMenu.Any())
        {
            JvDetailMenu = _tempProductMenu;
        }
    }
}

ModifyJvDetailViewModel.cs

public class ModifyJvDetailViewModel : JvDetailViewModelBase
{
    private readonly BackgroundWorker _worker = new BackgroundWorker();

    private IEnumerable<JvDetail> _tempLoadJvDetails;

    private readonly IJvDetailAppService _jvDetailAppService;

    private void worker_DoWork(object sender, DoWorkEventArgs e)
    {
        int ab = _jvDetailAppService.GetByCompanyId(3).Count(); // it is returning null here and everywhere which is fetching records.
        _tempLoadJvDetails = _jvDetailAppService.GetByCompanyId(3);
    }
    private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        JvDetails = _tempLoadJvDetails;
    }
    public override string Name
    {
        get { return JustAppHelper.JvDetail; }
    }

    public override string Icon
    {
        get { return JustAppHelper.JvDetailIcon; }
    }


    public ModifyJvDetailViewModel(IJvDetailAppService jvDetailAppService)
    {
        _jvDetailAppService = jvDetailAppService;
        var ab = _jvDetailAppService.GetAll().Count();

        _worker.DoWork += worker_DoWork;
        _worker.RunWorkerCompleted += worker_RunWorkerCompleted;
        _worker.RunWorkerAsync();
        BindGrid();

    }

    protected void BindGrid()
    {
        JvDetails = _jvDetailAppService.GetByCompanyId(3);
    }

    private IEnumerable<JvDetail> _jvDetails;
    public IEnumerable<JvDetail> JvDetails
    {
        get { return _jvDetails; }
        set
        {
            _jvDetails = value;
            RaisedPropertyChanged("JvDetails");
        }
    }
}

Mainwindow.cs

public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            this.DataContext = new MainWindowViewModel();
            ListBoxProducts.SelectedIndex = 0;
        }
    }

Answer 1

One approach would be to change MainWindowViewModel constructor:

public MainWindowViewModel(IJvDetailAppService detailAppService)
{
    _jvDetailAppService = detailAppService;

    _worker.DoWork += worker_DoWork;
    _worker.RunWorkerCompleted += worker_RunWorkerCompleted;
    _worker.RunWorkerAsync();
}

and MainWindow constructor:

public MainWindow(IJvDetailAppService detailAppService)
{
    InitializeComponent();
    this.DataContext = new MainWindowViewModel(detailAppService);
    ListBoxProducts.SelectedIndex = 0;
}