ArcGIS Pro 2.8 API Reference Guide
ZoomOutFixed Method
Example 

ArcGIS.Desktop.Mapping Namespace > MapView Class : ZoomOutFixed Method
The amount of time to navigate the view to the new camera position. If null it uses the default navigation duration.
Zoom the Camera out by a fixed amount. This method must be called on the MCT. Use QueuedTask.Run.
Syntax
public bool ZoomOutFixed( 
   Nullable<TimeSpan> duration
)
Public Function ZoomOutFixed( _
   Optional ByVal duration As Nullable(Of TimeSpan) _
) As Boolean

Parameters

duration
The amount of time to navigate the view to the new camera position. If null it uses the default navigation duration.

Return Value

True if the navigation is completed, false if it was interrupted by another view navigation.
Exceptions
ExceptionDescription
This method or property must be called within the lambda passed to QueuedTask.Run.
Example
Zoom out in the map view by a fixed amount.
public Task<bool> ZoomOutFixedAsync()
{
  return QueuedTask.Run(() =>
  {
    //Get the active map view.
    var mapView = MapView.Active;
    if (mapView == null)
      return false;

    //Zoom out in the map view by a fixed amount.
    return mapView.ZoomInFixed();
  });

}
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

MapView Class
MapView Members