ArcGIS Pro 2.4 API Reference Guide
SetVisible Method
Example 

ArcGIS.Desktop.Layouts Namespace > Element Class : SetVisible Method
Boolean
Sets the visibility of an element on a page layout. This method must be called on the MCT. Use QueuedTask.Run.
Syntax
Public Sub SetVisible( _
   ByVal isVisible As Boolean _
) 
public void SetVisible( 
   bool isVisible
)

Parameters

isVisible
Boolean
Exceptions
ExceptionDescription
This method must be called within the lambda passed to QueuedTask.Run.
Remarks
A value of true displays the element on the page layout.
Example
//Modify an element's visibility.

//Perform on the worker thread
await QueuedTask.Run(() =>
{
  element.SetVisible(true);  //Turn it on / make visible.
});
Requirements

Target Platforms: Windows 10, Windows 8.1, Windows 7

See Also

Reference

Element Class
Element Members