SelectElements(MapView,GraphicsLayer,Geometry,SelectionCombinationMethod,Boolean) Method

In This Topic

Select elements on a graphics layer that visually intersect a geometry. This method must be called on the MCT. Use QueuedTask.Run.

Syntax

C#
Visual Basic (Declaration)

public static IReadOnlyList<Element> SelectElements( 
   MapView mapView,
   GraphicsLayer graphicsLayer,
   Geometry geometry,
   SelectionCombinationMethod method,
   bool isWhollyWithin
)

Public Overloads Shared Function SelectElements( _
   ByVal mapView As MapView, _
   ByVal graphicsLayer As GraphicsLayer, _
   ByVal geometry As Geometry, _
   Optional ByVal method As SelectionCombinationMethod, _
   Optional ByVal isWhollyWithin As Boolean _
) As IReadOnlyList(Of Element)

Parameters

mapView: The mapView that contains the graphics layer..
graphicsLayer: The graphicsLayer whose elements will be selected
geometry: The selection geometry
method: Combination method used in selection operation
isWhollyWithin: This parameter only applies to 2D. Indicates whether only features that are completely within the geometry should be selected.

Return Value

IReadOnlyList

Exceptions

Exception	Description
ArcGIS.Core.CalledOnWrongThreadException	This method or property must be called within the lambda passed to QueuedTask.Run.
System.ArgumentException	geometry cannot be null or empty
System.InvalidOperationException	graphics layer is not associated with this view

Remarks

Currently, graphics layers are only supported for 2D.
Selection against elements always uses visual intersection as opposed to geometric intersection (of the search geometry with the element geometry). The graphics layer must be visible and selectable.
Use SelectElements(MapView,Geometry,SelectionCombinationMethod,Boolean) to select against all visible graphics layers.

Example

Spatial selection of elements in all Graphics Layers

//Map Tool is used to perform Spatial selection.
//Graphic selection uses the selection geometry 
//to intersect the geometries of those elements (graphic or group) 
//that will be selected and then highlights them. 
protected override async Task<bool> OnSketchCompleteAsync(Geometry geometry)
{
  var selPoly = geometry as Polygon;
  return await QueuedTask.Run(() =>
  {     
    //note: the selected elements may belong to more than one layer...
    var elems = MapView.Active.SelectElements(selPoly, SelectionCombinationMethod.New);
    return true;
  });
}

Spatial selection of elements in one graphics layer

//on the QueuedTask
//Create an extent to use for the spatial selection
var extent = MapView.Active.Extent;
var selectionExtent = extent.Expand(0.5, 0.5, true);
//Select elements in specified graphics layer using the selection extent.
var selectedElements = MapView.Active.SelectElements(graphicsLayer, selectionExtent, SelectionCombinationMethod.Add);

Spatial selection of elements in one graphics layer

//on the QueuedTask
//Create an extent to use for the spatial selection
var extent = MapView.Active.Extent;
var selectionExtent = extent.Expand(0.5, 0.5, true);
//Select elements in specified graphics layer using the selection extent.
var selectedElements = MapView.Active.SelectElements(graphicsLayer, selectionExtent, SelectionCombinationMethod.Add);

Select Text Graphic Elements

var graphicsLayer = MapView.Active.Map.GetLayersAsFlattenedList()
                    .OfType<ArcGIS.Desktop.Mapping.GraphicsLayer>().FirstOrDefault();
if (graphicsLayer == null)
  return;
var all_text = graphicsLayer.GetElementsAsFlattenedList()
              .Where(e => e.GetGraphic() is CIMTextGraphic);

Select Text Graphic Elements

var graphicsLayer = MapView.Active.Map.GetLayersAsFlattenedList()
                    .OfType<ArcGIS.Desktop.Mapping.GraphicsLayer>().FirstOrDefault();
if (graphicsLayer == null)
  return;
var all_text = graphicsLayer.GetElementsAsFlattenedList()
              .Where(e => e.GetGraphic() is CIMTextGraphic);

Requirements

Target Platforms: Windows 11, Windows 10, Windows 8.1

Reference

MappingExtensions Class
MappingExtensions Members
Overload List

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