How to: Set an Active Worksheet
// Set the second worksheet ("Sheet2") as the active worksheet. workbook.Worksheets.ActiveWorksheet = workbook.Worksheets["Sheet2"];
The image below shows the worksheet that is set as the active worksheet in a workbook (“Sheet2”).
The SpreadsheetControl.ActiveSheetChanging and SpreadsheetControl.ActiveSheetChanged events are raised before and after the active worksheet is changed via the control’s Sheet Tab Selector, respectively.