ArcGIS Pro 2.7 API Reference Guide
FindPageNumber Method
Example 

ArcGIS.Desktop.Layouts Namespace > MapSeries Class : FindPageNumber Method
Returns a map series page number based on the name field value of the index feature.
Syntax
public string FindPageNumber( 
   string pageName
)
Public Function FindPageNumber( _
   ByVal pageName As String _
) As String

Parameters

pageName
Remarks
Setting the current page requires specifying the approproriate page numnber. This helper function returns the page number associated with a page name.
Example
//Return the page number that corresponds to the page name field for an index feature

Layout layout = LayoutView.Active.Layout;

//Perform on the worker thread
await QueuedTask.Run(() =>
{
  SpatialMapSeries SMS = layout.MapSeries as SpatialMapSeries;
  Row msRow = SMS.CurrentRow;
  System.Windows.MessageBox.Show(SMS.FindPageNumber(msRow.GetOriginalValue(msRow.FindField("NAME")).ToString()));
});
Requirements

Target Platforms: Windows 10, Windows 8.1

See Also

Reference

MapSeries Class
MapSeries Members