Identify raster cell

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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 // Copyright 2020 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 ArcGIS.Samples.Managers; using Esri.ArcGISRuntime.Data; using Esri.ArcGISRuntime.Mapping; using Esri.ArcGISRuntime.Rasters; using Esri.ArcGISRuntime.UI; using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows; using System.Windows.Input;  namespace ArcGIS.WPF.Samples.IdentifyRasterCell {  [ArcGIS.Samples.Shared.Attributes.Sample(  name: "Identify raster cell",  category: "Layers",  description: "Get the cell value of a local raster at the tapped location and display the result in a callout.",  instructions: "Tap or move your cursor over an area of the raster to identify a raster cell and display it's attributes in a callout.",  tags: new[] { "NDVI", "band", "cell", "cell value", "continuous", "discrete", "identify", "pixel", "pixel value", "raster" })]  [ArcGIS.Samples.Shared.Attributes.OfflineData("b5f977c78ec74b3a8857ca86d1d9b318")]  public partial class IdentifyRasterCell  {  // Raster layer to display raster data on the map.  private RasterLayer _rasterLayer;   // Boolean to prevent concurrent identify calls.  private bool _isIdentifying = false;   // Store the next identify cell task.  private Action _nextIdentifyAction = null;   public IdentifyRasterCell()  {  InitializeComponent();  _ = Initialize();  }   private async Task Initialize()  {  // Define a new map with Wgs84 Spatial Reference.  var map = new Map(BasemapStyle.ArcGISOceans);  map.InitialViewpoint = new Viewpoint(-34.1, 18.6, 9);   // Get the file name for the raster.  string filepath = DataManager.GetDataFolder("b5f977c78ec74b3a8857ca86d1d9b318", "SA_EVI_8Day_03May20.tif");   // Load the raster file.  var raster = new Raster(filepath);   // Initialize the raster layer.  _rasterLayer = new RasterLayer(raster);   // Add the raster layer to the map.  map.OperationalLayers.Add(_rasterLayer);   // Add map to the map view.  MyMapView.Map = map;   try  {  // Wait for the layer to load.  await _rasterLayer.LoadAsync();   // Set the viewpoint.  await MyMapView.SetViewpointGeometryAsync(_rasterLayer.FullExtent);  }  catch (Exception ex)  {  MessageBox.Show(ex.Message, ex.GetType().ToString());  }   // Listen for mouse movement to start the identify operation.  MyMapView.MouseMove += MouseMoved;   // Disable magnifier.  MyMapView.InteractionOptions = new MapViewInteractionOptions  {  IsMagnifierEnabled = false  };  }   private void MouseMoved(object sender, MouseEventArgs mouseArgs)  {  // Get the curent mouse position.  Point position = mouseArgs.GetPosition(MyMapView);   // Identify the raster cell at that position.  _ = IdentifyCell(position);  }   private async Task IdentifyCell(Point position)  {  // Check if a cell is already being identified.  if (_isIdentifying)  {  _nextIdentifyAction = () => _ = IdentifyCell(position);  return;  }   // Set variable to true to prevent concurrent identify calls.  _isIdentifying = true;   try  {  // Get the result for where the user hovered on the raster layer.  IdentifyLayerResult identifyResult = await MyMapView.IdentifyLayerAsync(_rasterLayer, position, 1, false, 1);   // If no cell was identified, dismiss the callout.  if (!identifyResult.GeoElements.Any())  {  MyMapView.DismissCallout();  return;  }   // Create a StringBuilder to display information to the user.  var stringBuilder = new StringBuilder();   // Get the identified raster cell.  GeoElement cell = identifyResult.GeoElements.First();   // Loop through the attributes (key/value pairs).  foreach (KeyValuePair<string, object> keyValuePair in cell.Attributes)  {  // Add the key/value pair to the string builder.  stringBuilder.AppendLine($"{keyValuePair.Key}: {keyValuePair.Value}");  }   // Get the x and y values of the cell.  double x = cell.Geometry.Extent.XMin;  double y = cell.Geometry.Extent.YMin;   // Add the X & Y coordinates where the user clicked raster cell to the string builder.  stringBuilder.AppendLine($"X: {Math.Round(x, 4)}\nY: {Math.Round(y, 4)}");   // Create a callout using the string.  var definition = new CalloutDefinition(stringBuilder.ToString());   // Display the call out in the map view.  MyMapView.ShowCalloutAt(MyMapView.ScreenToLocation(position), definition);  }  catch (Exception ex)  {  MessageBox.Show(ex.Message, ex.GetType().ToString());  }  finally  {  _isIdentifying = false;  }   // Check if there is a new position to identify.  if (_nextIdentifyAction != null)  {  Action action = _nextIdentifyAction;   // Clear the queued identify action.  _nextIdentifyAction = null;   // Run the next action.  action();  }  }  } }