Xamarin的Prism，INavigationService的依赖项失败

我正在使用PRISM为iOS开发Xamarin.Forms应用程序示例。

但当我尝试在ViewModel中使用INavigationService时，它失败了，说接口INavigationService的依赖性失败

我不知道我做错了什么，我们怎么能绕过它，或者这是INavigationServices注入中的一个错误。

谢谢Divikiran Ravela

这是代码

    public App()
    {
        // The root page of your application
        Prism = new PrismBootStrap();
        Prism.Run(this);
    }
    public class PrismBootStrap : UnityBootstrapper
{
    protected override Page CreateMainPage()
    {
        return new NavigationPage(Container.Resolve<HomePage>());
    }
    protected override void RegisterTypes()
    {
        Container.RegisterTypeForNavigation<HomePage, HomePageViewModel>();
    }
}

    public class HomePage : ContentPage
    {
        public HomePageViewModel ViewModel { get; set; }

   public HomePage()
    {
        ViewModel = App.Prism.Container.Resolve<HomePageViewModel>();
        Content = new StackLayout
        {
            Children = {
                new Label { Text = "Hello ContentPage" }
            }
        };
    }
}

public class HomePageViewModel : BindableBase
{
    private readonly INavigationService _navigationService;
    public HomePageViewModel(INavigationService navigationService)
    {
        _navigationService = navigationService; //Fails here
    }
}