Sets or returns whether the PivotTable will display in classic layout mode

 public boolean ClassicLayout{ get; set; }
Public Property ClassicLayout() As Boolean

          ExcelApplication xla = new ExcelApplication();
          Workbook wb = xla.Open(@"C:\MySpreadsheet.xlsx");
          Worksheet ws = wb.Worksheets[0];
          ws.PivotTables[0].PivotTableSettings.ClassicLayout = true;

          Dim xla As New ExcelApplication()
          Dim wb As Workbook = xla.Open("C:\MySpreadsheet.xlsx")
          Dim ws As Worksheet = wb.Worksheets(0)
          ws.PivotTables(0).PivotTableSettings.ClassicLayout = true;

This property corresponds to the Classic PivotTable layout setting under PivotTable Options on the display tab. This enables the ability to drag and drop fields in the PivotTable grid.

The default value of ClassicLayout is false for PivotTables generated by ExcelWriter.