Create a feature collection layer from a portal item.
      
   
    
Use case
Feature collection layers are often used to hold features with mixed geometry or unstructured data. You can display feature collections stored in a Portal, which are often used for showing content from a CSV or map notes.
How to use the sample
The feature collection is loaded from the Portal item when the sample starts.
How it works
- Create a Portal.
- Create the PortalItem, referring to the portal and an item ID.
- Verify that the item represents a feature collection.
- Create a FeatureCollectionfrom the item.
- Create a FeatureCollectionLayer, referring to the feature collection.
- Add the feature collection layer to the map's OperationalLayerscollection.
Relevant API
- FeatureCollection
- FeatureCollectionLayer
- Portal
- PortalItem
About the data
The sample uses a sample layer depicting world populations.
Tags
collection, feature collection, feature collection layer, id, item, map notes, portal
Sample Code
// Copyright 2018 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;
using System;
using System.Threading.Tasks;
using System.Windows;
namespace ArcGIS.WPF.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
    {
        // Default portal item Id to load features from.
        private const string FeatureCollectionItemId = "32798dfad17942858d5eef82ee802f0b";
        public FeatureCollectionLayerFromPortal()
        {
            InitializeComponent();
            // Call a function to set up the map and UI.
            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 featCollection = new FeatureCollection(collectionItem);
                    // Create a layer to display the collection and add it to the map as an operational layer.
                    FeatureCollectionLayer featCollectionLayer = new FeatureCollectionLayer(featCollection)
                    {
                        Name = collectionItem.Title
                    };
                    MyMapView.Map.OperationalLayers.Add(featCollectionLayer);
                }
                else
                {
                    MessageBox.Show("Portal item with ID '" + itemId + "' is not a feature collection.", "Feature Collection");
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show("Unable to open item with ID '" + itemId + "': " + ex.Message, "Error");
            }
        }
        private void OpenPortalFeatureCollectionClick(object sender, RoutedEventArgs e)
        {
            // Get the portal item Id from the user.
            string collectionItemId = CollectionItemIdTextBox.Text.Trim();
            // Make sure an Id was entered.
            if (String.IsNullOrEmpty(collectionItemId))
            {
                MessageBox.Show("Please enter a portal item ID", "Feature Collection ID");
                return;
            }
            // Call a function to add the feature collection from the specified portal item.
            _ = OpenFeaturesFromArcGISOnline(collectionItemId);
        }
    }
}