ArcGIS Pro 2.8 API Reference Guide
ZoomToPageWidth Method (LayoutView)
Example 

ArcGIS.Desktop.Layouts Namespace > LayoutView Class : ZoomToPageWidth Method
The amount of time to navigate the view to the new camera position. If null it uses the default navigation duration.
Zoom the layout view to the width of the page. This method must be called on the MCT. Use QueuedTask.Run.
Syntax
public bool ZoomToPageWidth( 
   Nullable<TimeSpan> duration
)
Public Function ZoomToPageWidth( _
   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

Returns true if the navigation is completed, false if it was interrupted by another view navigation.
Exceptions
ExceptionDescription
This method must be called within the lambda passed to QueuedTask.Run.
Example
//Set the layout view extent to accomodate the width of the page.

//Process on worker thread
await QueuedTask.Run(() =>
{
  layoutView.ZoomToPageWidth();
});
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

LayoutView Class
LayoutView Members