ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Desktop.Mapping Namespace / MapView Class / Extent Property
Example Version

Extent Property (MapView)
Gets the current extent of the view.
Syntax
public Envelope Extent {get;}
Remarks
Use this in combination with ZoomTo(Geometry,Nullable<TimeSpan>,Boolean) to get and set the view's extent.
Example
Expand Extent
public Task<bool> ExpandExtentAsync(double dx, double dy)
{
  return QueuedTask.Run(() =>
  {
    //Get the active map view.
    var mapView = MapView.Active;
    if (mapView == null)
      return false;

    //Expand the current extent by the given ratio.
    var extent = mapView.Extent;
    var newExtent = ArcGIS.Core.Geometry.GeometryEngine.Instance.Expand(extent, dx, dy, true);
    return mapView.ZoomTo(newExtent);
  });
}
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also