CreateFeatureCollectionLayer.xaml.cs

// 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.Geometry;
using Esri.ArcGISRuntime.Mapping;
using Esri.ArcGISRuntime.Symbology;

using Colors = System.Drawing.Color;

namespace ArcGIS.Samples.CreateFeatureCollectionLayer
{
    [ArcGIS.Samples.Shared.Attributes.Sample(
        name: "Feature collection layer",
        category: "Layers",
        description: "Create a Feature Collection Layer from a Feature Collection Table, and add it to a map.",
        instructions: "When launched, this sample displays a `FeatureCollectionLayer` with a `Point`, `Polyline` and `Polygon` geometry.",
        tags: new[] { "feature collection", "layers" })]
    public partial class CreateFeatureCollectionLayer : ContentPage
    {
        public CreateFeatureCollectionLayer()
        {
            InitializeComponent();

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

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

            // Call a function that will create a new feature collection layer and zoom to it
            _ = CreateNewFeatureCollection();
        }

        private async Task CreateNewFeatureCollection()
        {
            // Create the schema for a points table (one text field to contain a name attribute)
            List<Field> pointFields = new List<Field>();
            Field placeField = new Field(FieldType.Text, "Place", "Place Name", 50);
            pointFields.Add(placeField);

            // Create the schema for a lines table (one text field to contain a name attribute)
            List<Field> lineFields = new List<Field>();
            Field boundaryField = new Field(FieldType.Text, "Boundary", "Boundary Name", 50);
            lineFields.Add(boundaryField);

            // Create the schema for a polygon table (one text field to contain a name attribute)
            List<Field> polyFields = new List<Field>();
            Field areaField = new Field(FieldType.Text, "AreaName", "Area Name", 50);
            polyFields.Add(areaField);

            // Instantiate FeatureCollectionTables with schema and geometry type
            FeatureCollectionTable pointsTable = new FeatureCollectionTable(pointFields, GeometryType.Point, SpatialReferences.Wgs84);
            FeatureCollectionTable linesTable = new FeatureCollectionTable(lineFields, GeometryType.Polyline, SpatialReferences.Wgs84);
            FeatureCollectionTable polysTable = new FeatureCollectionTable(polyFields, GeometryType.Polygon, SpatialReferences.Wgs84);

            // Set rendering for each table
            pointsTable.Renderer = CreateRenderer(GeometryType.Point);
            linesTable.Renderer = CreateRenderer(GeometryType.Polyline);
            polysTable.Renderer = CreateRenderer(GeometryType.Polygon);

            // Create a new point feature, provide geometry and attribute values
            Feature pointFeature = pointsTable.CreateFeature();
            pointFeature.SetAttributeValue(placeField, "Current location");
            MapPoint point1 = new MapPoint(-79.497238, 8.849289, SpatialReferences.Wgs84);
            pointFeature.Geometry = point1;

            // Create a new line feature, provide geometry and attribute values
            Feature lineFeature = linesTable.CreateFeature();
            lineFeature.SetAttributeValue(boundaryField, "AManAPlanACanalPanama");
            MapPoint point2 = new MapPoint(-80.035568, 9.432302, SpatialReferences.Wgs84);
            Polyline line = new Polyline(new MapPoint[] { point1, point2 });
            lineFeature.Geometry = line;

            // Create a new polygon feature, provide geometry and attribute values
            Feature polyFeature = polysTable.CreateFeature();
            polyFeature.SetAttributeValue(areaField, "Restricted area");
            MapPoint point3 = new MapPoint(-79.337936, 8.638903, SpatialReferences.Wgs84);
            MapPoint point4 = new MapPoint(-79.11409, 8.895422, SpatialReferences.Wgs84);
            Polygon poly = new Polygon(new MapPoint[] { point1, point3, point4 });
            polyFeature.Geometry = poly;

            try
            {
                // Add the new features to the appropriate feature collection table
                await pointsTable.AddFeatureAsync(pointFeature);
                await linesTable.AddFeatureAsync(lineFeature);
                await polysTable.AddFeatureAsync(polyFeature);

                // Create a feature collection and add the feature collection tables
                FeatureCollection featuresCollection = new FeatureCollection();
                featuresCollection.Tables.Add(pointsTable);
                featuresCollection.Tables.Add(linesTable);
                featuresCollection.Tables.Add(polysTable);

                // Create a FeatureCollectionLayer
                FeatureCollectionLayer collectionLayer = new FeatureCollectionLayer(featuresCollection);

                // When the layer loads, zoom the map centered on the feature collection
                await collectionLayer.LoadAsync();
                await MyMapView.SetViewpointCenterAsync(collectionLayer.FullExtent.GetCenter(), 1000000);

                // Add the layer to the Map's Operational Layers collection
                MyMapView.Map.OperationalLayers.Add(collectionLayer);
            }
            catch (Exception e)
            {
                await Application.Current.MainPage.DisplayAlert("Error", e.ToString(), "OK");
            }
        }

        private Renderer CreateRenderer(GeometryType rendererType)
        {
            // Return a simple renderer to match the geometry type provided
            Symbol sym = null;

            switch (rendererType)
            {
                case GeometryType.Point:
                case GeometryType.Multipoint:
                    // Create a marker symbol
                    sym = new SimpleMarkerSymbol(SimpleMarkerSymbolStyle.Triangle, Colors.Red, 18);
                    break;

                case GeometryType.Polyline:
                    // Create a line symbol
                    sym = new SimpleLineSymbol(SimpleLineSymbolStyle.Dash, Colors.Green, 3);
                    break;

                case GeometryType.Polygon:
                    // Create a fill symbol
                    SimpleLineSymbol lineSym = new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, Colors.DarkBlue, 2);
                    sym = new SimpleFillSymbol(SimpleFillSymbolStyle.DiagonalCross, Colors.Cyan, lineSym);
                    break;

                default:
                    break;
            }

            // Return a new renderer that uses the symbol created above
            return new SimpleRenderer(sym);
        }
    }
}