How Populate Excel Worksheets name to dropdown

Question

want to fetch Excel worksheet name and bind it to dropdown list, I've tried 

try

{

var document = SpreadsheetDocument.Open(file.InputStream, false);

workbookPart = document.WorkbookPart;

var sheets = workbookPart.Workbook.Descendants<Sheet>();

var sheet = sheets.First();

data.SheetName = sheet.Name;

}

 

by this I get 1st sheet name in var sheet but excel file having multiple sheets and I want to get all

Help!