ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Desktop.Mapping Namespace / SelectionEnvironment Class / SelectionTolerance Property
Example Version

SelectionTolerance Property (SelectionEnvironment)
Gets the search tolerance in device units.
Syntax
public static int SelectionTolerance {get;}
Example
Calculate Selection tolerance in map units
//Selection tolerance for the map in pixels
var selectionTolerance = SelectionEnvironment.SelectionTolerance;
QueuedTask.Run(() =>
{
  //Get the map center
  var mapExtent = MapView.Active.Map.GetDefaultExtent();
  var mapPoint = mapExtent.Center;
  //Map center as screen point
  var screenPoint = MapView.Active.MapToScreen(mapPoint);
  //Add selection tolerance pixels to get a "radius".
  var radiusScreenPoint = new System.Windows.Point((screenPoint.X + selectionTolerance), screenPoint.Y);
  var radiusMapPoint = MapView.Active.ScreenToMap(radiusScreenPoint);
  //Calculate the selection tolerance distance in map uints.
  var searchRadius = GeometryEngine.Instance.Distance(mapPoint, radiusMapPoint);
});
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also