Create feature collection layer (Portal item)

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage x:Class="ArcGIS.Samples.FeatureCollectionLayerFromPortal.FeatureCollectionLayerFromPortal"
             xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:esriUI="clr-namespace:Esri.ArcGISRuntime.Maui;assembly=Esri.ArcGISRuntime.Maui">

    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition />
            <RowDefinition Height="40" />
            <RowDefinition Height="40" />
        </Grid.RowDefinitions>
        <esriUI:MapView x:Name="MyMapView" Grid.Row="0" />
        <Entry x:Name="CollectionItemIdTextBox"
               Grid.Row="1"
               HorizontalOptions="Fill"
               Placeholder="Portal item Id" />
        <Button Grid.Row="2"
                Clicked="OpenPortalFeatureCollectionClick"
                HorizontalOptions="Fill"
                Text="Open feature collection item" />
    </Grid>
</ContentPage>

// Copyright 2022 Esri.
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
// You may obtain a copy of the License at: http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific
// language governing permissions and limitations under the License.

using Esri.ArcGISRuntime.Data;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Portal;

namespace ArcGIS.Samples.FeatureCollectionLayerFromPortal
{
    [ArcGIS.Samples.Shared.Attributes.Sample(
        name: "Create feature collection layer (Portal item)",
        category: "Layers",
        description: "Create a feature collection layer from a portal item.",
        instructions: "The feature collection is loaded from the Portal item when the sample starts.",
        tags: new[] { "collection", "feature collection", "feature collection layer", "id", "item", "map notes", "portal" })]
    public partial class FeatureCollectionLayerFromPortal : ContentPage
    {
        // Default portal item Id to load features from.
        private const string FeatureCollectionItemId = "32798dfad17942858d5eef82ee802f0b";

        public FeatureCollectionLayerFromPortal()
        {
            InitializeComponent();

            // call a function to initialize a map to display in the MyMapView control.
            Initialize();
        }

        private void Initialize()
        {
            // Add a default value for the portal item Id.
            CollectionItemIdTextBox.Text = FeatureCollectionItemId;

            // Create a new map with the oceans basemap and add it to the map view.
            Map myMap = new Map(BasemapStyle.ArcGISOceans);
            MyMapView.Map = myMap;
        }

        private async Task OpenFeaturesFromArcGISOnline(string itemId)
        {
            try
            {
                // Open a portal item containing a feature collection.
                ArcGISPortal portal = await ArcGISPortal.CreateAsync();
                PortalItem collectionItem = await PortalItem.CreateAsync(portal, itemId);

                // Verify that the item is a feature collection.
                if (collectionItem.Type == PortalItemType.FeatureCollection)
                {
                    // Create a new FeatureCollection from the item.
                    FeatureCollection featureCollection = new FeatureCollection(collectionItem);

                    // Create a layer to display the collection and add it to the map as an operational layer.
                    FeatureCollectionLayer featureCollectionLayer = new FeatureCollectionLayer(featureCollection)
                    {
                        Name = collectionItem.Title
                    };

                    MyMapView.Map.OperationalLayers.Add(featureCollectionLayer);
                }
                else
                {
                    await Application.Current.Windows[0].Page.DisplayAlert("Feature Collection", "Portal item with ID '" + itemId + "' is not a feature collection.", "OK");
                }
            }
            catch (Exception ex)
            {
                await Application.Current.Windows[0].Page.DisplayAlert("Error", "Unable to open item with ID '" + itemId + "': " + ex.Message, "OK");
            }
        }

        private void OpenPortalFeatureCollectionClick(object sender, EventArgs e)
        {
            // Get the portal item Id from the user.
            string collectionItemId = CollectionItemIdTextBox.Text.Trim();

            // Make sure an Id was entered.
            if (String.IsNullOrEmpty(collectionItemId))
            {
                _ = DisplayAlert("Feature Collection ID", "Please enter a portal item ID", "OK");
                return;
            }

            // Call a function to add the feature collection from the specified portal item.
            _ = OpenFeaturesFromArcGISOnline(collectionItemId);
        }
    }
}