Dear Kanimozhi,
I asked to clear the workbook and not the active worksheet. For e.g. when you load the SfSpreadsheet control it shows only Sheet1 with empty worksheet.
When you load some excel sheet into it, then it create sheets according to the excel.
Here, my requirement is, I have a context menu for Spreadsheet control for clearing the loaded excel sheet from SfSpreadsheet control and display freshly the Sheet1.