Add MVVM prism in Xamarin form app.

app.xaml.cs

using Prism;
using Prism.Ioc;
using Xamarin.Forms;

namespace XamarinFormPrism
{
    public partial class App : Prism.Unity.PrismApplication
    {
        public App(IPlatformInitializer platformInitiliser = null) : base(platformInitiliser)
        {
        }

	protected override void OnInitialized()
	{
            InitializeComponent();
	}

	protected override void RegisterTypes(IContainerRegistry containerRegistry)
	{
            
	}

	protected override void OnStart()
        {
            // Handle when your app starts
        }

        protected override void OnSleep()
        {
            // Handle when your app sleeps
        }

        protected override void OnResume()
        {
            // Handle when your app resumes
        }
    }
}