INavigation not working with Prism in Xamarin.Forms

I have decided to use prism with xamarin . found some articles to start with prism . I have installed 3 xamarin packages

1)Prism.Core
2)Prism.Forms
3)Prism.Unity.Forms

and inherits App from PrismApplication like This

public partial class App : PrismApplication {}

I don't want to use ViewModelLocator.AutowireViewModel="True" to bind view with Naming Conventions

I found this code to bind view with viewmodel without following naming convention

protected override void ConfigureViewModelLocator()
{
    base.ConfigureViewModelLocator();
    BindViewModelToView<LoginRegisterViewModel, MainPage>();
}
public void BindViewModelToView<TViewModel, TView>()
{
    ViewModelLocationProvider.Register(typeof(TView).ToString(), () => Container.Resolve<TViewModel>());
}

Here is my ViewModel

public class LoginRegisterViewModel : BindableBase
{
    #region Private variables
    private readonly IPageDialogService _diglogService;
    private readonly INavigationService _navigationService;
    #endregion

    #region Constructor
    public LoginRegisterViewModel(IPageDialogService diglogService, INavigationService navigationService)
    {
        _diglogService = diglogService;
         _navigationService = navigationService;

    }
    #endregion
}

When start a App it shows error

Unhandled Exception:
Microsoft.Practices.Unity.ResolutionFailedException: Resolution of the dependency failed, type = "DSMobile.ViewModels.LoginRegisterViewModel", name = "(none)".

Exception occurred while: while resolving.

Exception is: InvalidOperationException - The current type, Prism.Navigation.INavigationService, is an interface and cannot be constructed. Are you missing a type mapping?

At the time of the exception, the container was:

Resolving DSMobile.ViewModels.LoginRegisterViewModel,(none)

Resolving parameter "navigationService" of constructor DSMobile.ViewModels.LoginRegisterViewModel(Prism.Services.IPageDialogService diglogService, Prism.Navigation.INavigationService navigationService)

Resolving Prism.Navigation.INavigationService,(none)

Dependency Injection not working . while not using naming conventions . It works fine when using naming convention binding

Please help . how can i bind views with viewmodel without naming conventions . suggestion are most welcome

Thanks in advance