Prism Tabbed Navigation

BehaviorBase{T}.cs

    public class BehaviorBase<T> : Behavior<T> where T : BindableObject
    {
        public T AssociatedObject { get; private set; }

        protected override void OnAttachedTo( T bindable )
        {
            base.OnAttachedTo( bindable );
            AssociatedObject = bindable;

            if( bindable.BindingContext != null )
            {
                BindingContext = bindable.BindingContext;
            }

            bindable.BindingContextChanged += OnBindingContextChanged;
        }

        protected override void OnDetachingFrom( T bindable )
        {
            base.OnDetachingFrom( bindable );
            bindable.BindingContextChanged -= OnBindingContextChanged;
            AssociatedObject = null;
        }

        void OnBindingContextChanged( object sender, EventArgs e )
        {
            OnBindingContextChanged();
        }

        protected override void OnBindingContextChanged()
        {
            base.OnBindingContextChanged();
            BindingContext = AssociatedObject.BindingContext;
        }
    }

IMultiPageNavigationAware.cs

    public interface IMultiPageNavigationAware
    {
        void OnInternalNavigatedFrom( NavigationParameters navParams );
        void OnInternalNavigatedTo( NavigationParameters navParams );
    }

MultiPageNavigationBehavior.cs

    public class MultiPageNavigationBehavior : BehaviorBase<MultiPage<Page>>
    {
        private Page _lastSelectedPage;

        protected override void OnAttachedTo( MultiPage<Page> bindable )
        {
            base.OnAttachedTo( bindable );
            bindable.CurrentPageChanged += CurrentPageChangedHandler;
        }

        protected override void OnDetachingFrom( MultiPage<Page> bindable )
        {
            base.OnDetachingFrom( bindable );
            bindable.CurrentPageChanged -= CurrentPageChangedHandler;
        }

        private void CurrentPageChangedHandler( object sender, EventArgs args )
        {
            NavigationParameters parameters = new NavigationParameters();

            var lastPageContextAware = _lastSelectedPage?.BindingContext as IMultiPageNavigationAware;
            lastPageContextAware?.OnInternalNavigatedFrom( parameters );
            
            var newPageContextAware = AssociatedObject.CurrentPage.BindingContext as IMultiPageNavigationAware;
            newPageContextAware?.OnInternalNavigatedTo( parameters );

            _lastSelectedPage = AssociatedObject.CurrentPage;
        }
    }

How would you get the navigation parameters from the the multipage to the content page?

Update: Nevermind, just put values from the previous page into the parameters when they are passed to OnNavigateFrom

This doesn't handle passing NavigationParameters from the MultiPage (TabbedPage) to the Children. If you feel there is a need for that please update the Prism issue and I'll see what we can do.

Thank you so much for this! I changed it to use IActiveAware instead since I'm used to that with WPF. I don't need any parameters passed at this time, but if I do I may end up switching back to this.

Could you share how you implemented it @JoshClose? please. I'm trying to implement the IActiveAware without success.