List related features

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 // 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 Esri.ArcGISRuntime.UI.Controls; using System; using System.Collections.Generic; using System.Drawing; using System.Linq; using System.Threading.Tasks; using System.Windows;  namespace ArcGIS.WPF.Samples.ListRelatedFeatures {  [ArcGIS.Samples.Shared.Attributes.Sample(  name: "List related features",  category: "Data",  description: "List features related to the selected feature.",  instructions: "Click on a feature to select it. The related features will be displayed in a list.",  tags: new[] { "features", "identify", "query", "related", "relationship", "search" })]  public partial class ListRelatedFeatures  {  // Hold the URL of the web map.  private readonly Uri _mapUri =  new Uri("https://arcgisruntime.maps.arcgis.com/home/item.html?id=dcc7466a91294c0ab8f7a094430ab437");   // Reference to the feature layer.  private FeatureLayer _myFeatureLayer;   public ListRelatedFeatures()  {  InitializeComponent();   // Create the UI, setup the control references and execute initialization.  _ = Initialize();  }   private async Task Initialize()  {  try  {  // Create the portal item from the URL to the webmap.  PortalItem alaskaPortalItem = await PortalItem.CreateAsync(_mapUri);   // Create the map from the portal item.  Map myMap = new Map(alaskaPortalItem);   // Add the map to the mapview.  MyMapView.Map = myMap;   // Wait for the map to load.  await myMap.LoadAsync();   // Get the feature layer from the map.  _myFeatureLayer = (FeatureLayer)myMap.OperationalLayers.First();   // Wait for the layer to load.  await _myFeatureLayer.LoadAsync();   // Make the selection color yellow.  MyMapView.SelectionProperties.Color = Color.Yellow;   // Listen for GeoViewTapped events.  MyMapView.GeoViewTapped += MyMapViewOnGeoViewTapped;   // Hide the loading indicator.  LoadingProgress.Visibility = Visibility.Collapsed;  }  catch (Exception e)  {  MessageBox.Show(e.ToString(), "Error");  }  }   private async void MyMapViewOnGeoViewTapped(object sender, GeoViewInputEventArgs e)  {  // Clear any existing feature selection and results list.  _myFeatureLayer.ClearSelection();  MyResultsView.ItemsSource = null;   try  {  // Identify the tapped feature.  IdentifyLayerResult results = await MyMapView.IdentifyLayerAsync(_myFeatureLayer, e.Position, 10, false);   // Return if there are no results.  if (results.GeoElements.Count < 1)  {  return;  }   // Show the loading indicator (this can take a while).  LoadingProgress.Visibility = Visibility.Visible;   // Get the first result.  ArcGISFeature myFeature = (ArcGISFeature)results.GeoElements.First();   // Select the feature.  _myFeatureLayer.SelectFeature(myFeature);   // Get the feature table for the feature.  ArcGISFeatureTable myFeatureTable = (ArcGISFeatureTable)myFeature.FeatureTable;   // Query related features.  IReadOnlyList<RelatedFeatureQueryResult> relatedFeaturesResult =  await myFeatureTable.QueryRelatedFeaturesAsync(myFeature);   // Create a list to hold the formatted results of the query.  List<string> queryResultsForUi = new List<string>();   // For each query result.  foreach (RelatedFeatureQueryResult result in relatedFeaturesResult)  {  // And then for each feature in the result.  foreach (Feature resultFeature in result)  {  // Get a reference to the feature's table.  ArcGISFeatureTable relatedTable = (ArcGISFeatureTable)resultFeature.FeatureTable;   // Get the display field name - this is the name of the field that is intended for display.  string displayFieldName = relatedTable.LayerInfo.DisplayFieldName;   // Get the name of the feature's table.  string tableName = relatedTable.TableName;   // Get the display name for the feature.  string featureDisplayname = resultFeature.Attributes[displayFieldName].ToString();   // Create a formatted result string.  string formattedResult = string.Format("{0} - {1}", tableName, featureDisplayname);   // Add the result to the list.  queryResultsForUi.Add(formattedResult);  }  }   // Update the UI with the result list.  MyResultsView.ItemsSource = queryResultsForUi;   // Hide the loading indicator.  LoadingProgress.Visibility = Visibility.Collapsed;  }  catch (Exception ex)  {  MessageBox.Show(ex.ToString(), "Error");  }  }  } }