Xamarin.form Page Navigation in mvvm

Question

I am working on xamarin.form cross-platform application , i want to navigate from one page to another on button click. As i cannot do Navigation.PushAsync(new Page2());

Answer 1

my approach based on principle every View can navigate to VM context based places of the app only:

In ViewModel i declare INavigationHandler interfeces like that:

public class ItemsViewModel : ViewModelBase
{
    public INavigationHandler NavigationHandler { private get; set; }


    // some VM code here where in some place i'm invoking
    RelayCommand ItemSelectedCommand => 
        new RelayCommand((itemID) => { NavigationHandler.NavigateToItemDetail(itemID); });


    public interface INavigationHandler
    {
        void NavigateToItemDetail(int itemID);
    }
}

And assign code-behind class as INavigationHandler for ViewModel:

public class ItemsPage : ContentPage, ItemsViewModel.INavigationHandler
{
    ItemsViewModel viewModel;

    public ItemsPage()
    {
        viewModel = Container.Default.Get();
        viewModel.NavigationHandler = this;
    }


    public async void NavigateToItemDetail(int itemID)
    {
        await Navigation.PushAsync(new ItemDetailPage(itemID));
    }
}