<?xml version="1.0" encoding="utf-8"?>
<!-- xmlns:forms="clr-namespace:Lottie.Forms;assembly=Lottie.Forms"をお忘れなく！ -->
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" 
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
             xmlns:local="clr-namespace:LottieFormsSample" 
             x:Class="LottieFormsSample.LottieFormsSamplePage"
             xmlns:forms="clr-namespace:Lottie.Forms;assembly=Lottie.Forms">
    <ContentPage.Content>
        <StackLayout VerticalOptions="FillAndExpand" HorizontalOptions="FillAndExpand">
            <!-- ここがメインです！ -->
            <forms:AnimationView 
                x:Name="AnimationView" 
                Animation="City.json" 
                AutoPlay="True" Loop="true"
                VerticalOptions="FillAndExpand"
                HorizontalOptions="FillAndExpand" />
        </StackLayout>
    </ContentPage.Content>
</ContentPage>

using System;
using System.Collections.Generic;
using System.Linq;

using Foundation;
using UIKit;

// Lottie用に追加
using Lottie.Forms.iOS.Renderers;

namespace LottieFormsSample.iOS
{
    [Register("AppDelegate")]
    public partial class AppDelegate : global::Xamarin.Forms.Platform.iOS.FormsApplicationDelegate
    {
        public override bool FinishedLaunching(UIApplication app, NSDictionary options)
        {
            global::Xamarin.Forms.Forms.Init();

            LoadApplication(new App());

            // Lottie用に追加
            AnimationViewRenderer.Init();

            return base.FinishedLaunching(app, options);
        }
    }
}

using System;

using AppKit;
using Foundation;

using Airbnb.Lottie;

namespace LottiemacOSSample
{
    public partial class ViewController : NSViewController
    {
        private LOTAnimationView lottieLogo;

        public ViewController(IntPtr handle) : base(handle)
        {
        }

        public override void ViewDidLoad()
        {
            base.ViewDidLoad();

            this.lottieLogo = LOTAnimationView.AnimationNamed("LottieLogo1");
            this.lottieLogo.LoopAnimation = true;
            this.lottieLogo.ContentMode = LOTViewContentMode.ScaleAspectFill;
            this.lottieLogo.Frame = View.Bounds;
            this.lottieLogo.AutoresizingMask = NSViewResizingMask.WidthSizable |
               NSViewResizingMask.HeightSizable;
            this.View.AddSubview(this.lottieLogo);
        }

        public override void ViewDidAppear()
        {
            base.ViewDidAppear();
            this.lottieLogo.Play();
        }

        public override NSObject RepresentedObject
        {
            get
            {
                return base.RepresentedObject;
            }
            set
            {
                base.RepresentedObject = value;
                // Update the view, if already loaded.
            }
        }
    }
}