Browse OGC API feature service

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 // 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.Ogc; using Esri.ArcGISRuntime.Symbology; using System.Diagnostics; using Color = System.Drawing.Color;  namespace ArcGIS.Samples.BrowseOAFeatureService {  [ArcGIS.Samples.Shared.Attributes.Sample(  name: "Browse OGC API feature service",  category: "Layers",  description: "Browse an OGC API feature service for layers and add them to the map.",  instructions: "Select a layer to display from the list of layers shown in an OGC API service.",  tags: new[] { "OGC", "OGC API", "browse", "catalog", "feature", "layers", "service", "web" })]  public partial class BrowseOAFeatureService : ContentPage  {  // URL for the OGC feature service.  private const string ServiceUrl = "https://demo.ldproxy.net/daraa";   public BrowseOAFeatureService()  {  InitializeComponent();  Initialize();  }   private void Initialize()  {  // Init the UI.  ServiceTextBox.Text = ServiceUrl;   // Create the map with topographic basemap.  MyMapView.Map = new Map(BasemapStyle.ArcGISTopographic);  _ = LoadService();  }   private async Task LoadService()  {  try  {  LoadingProgressBar.IsVisible = true;  LoadLayersButton.IsEnabled = false;  LoadServiceButton.IsEnabled = false;   // Create the OGC API - Features service using the landing URL.  OgcFeatureService service = new OgcFeatureService(new Uri(ServiceTextBox.Text));   // Load the service.  await service.LoadAsync();   // Get the service metadata.  OgcFeatureServiceInfo serviceInfo = service.ServiceInfo;   // Get a list of available collections.  IEnumerable<OgcFeatureCollectionInfo> layerListReversed = serviceInfo.FeatureCollectionInfos;   // Show the layers in the UI.  OgcFeatureCollectionList.ItemsSource = layerListReversed;  }  catch (Exception ex)  {  Debug.WriteLine(ex);  await Application.Current.Windows[0].Page.DisplayAlert(ex.Message, "Error loading service", "OK");  }  finally  {  // Update the UI.  LoadingProgressBar.IsVisible = false;  LoadLayersButton.IsEnabled = true;  LoadServiceButton.IsEnabled = true;  }  }   private async void LoadLayers_Clicked(object sender, EventArgs e)  {  // Show the progress bar.  LoadingProgressBar.IsVisible = true;   // Clear the existing layers.  MyMapView.Map.OperationalLayers.Clear();   try  {  // Get the selected collection.  OgcFeatureCollectionInfo selectedCollectionInfo = (OgcFeatureCollectionInfo)OgcFeatureCollectionList.SelectedItem;   // Create the OGC feature collection table.  OgcFeatureCollectionTable table = new OgcFeatureCollectionTable(selectedCollectionInfo);   // Set the feature request mode to manual (only manual is currently supported).  // In this mode, you must manually populate the table - panning and zooming won't request features automatically.  table.FeatureRequestMode = FeatureRequestMode.ManualCache;   // Populate the OGC feature collection table.  QueryParameters queryParamaters = new QueryParameters();  queryParamaters.MaxFeatures = 1000;  await table.PopulateFromServiceAsync(queryParamaters, false, null);   // Create a feature layer from the OGC feature collection table.  FeatureLayer ogcFeatureLayer = new FeatureLayer(table);   // Choose a renderer for the layer based on the table.  ogcFeatureLayer.Renderer = GetRendererForTable(table) ?? ogcFeatureLayer.Renderer;   // Add the layer to the map.  MyMapView.Map.OperationalLayers.Add(ogcFeatureLayer);   // Zoom to the extent of the selected collection.  if (selectedCollectionInfo.Extent is Envelope collectionExtent && !collectionExtent.IsEmpty)  {  await MyMapView.SetViewpointGeometryAsync(collectionExtent, 100);  }  }  catch (Exception ex)  {  Debug.WriteLine(ex);  await Application.Current.Windows[0].Page.DisplayAlert(ex.Message, "Error loading service", "OK");  }  finally  {  // Hide the progress bar.  LoadingProgressBar.IsVisible = false;  }  }   private Renderer GetRendererForTable(FeatureTable table)  {  switch (table.GeometryType)  {  case GeometryType.Point:  case GeometryType.Multipoint:  return new SimpleRenderer(new SimpleMarkerSymbol(SimpleMarkerSymbolStyle.Circle, Color.Blue, 5));   case GeometryType.Polygon:  case GeometryType.Envelope:  return new SimpleRenderer(new SimpleFillSymbol(SimpleFillSymbolStyle.Solid, Color.Blue, null));   case GeometryType.Polyline:  return new SimpleRenderer(new SimpleLineSymbol(SimpleLineSymbolStyle.Solid, Color.Blue, 1));  }   return null;  }   private void LoadServiceButton_Click(object sender, EventArgs e)  {  _ = LoadService();  }  } }