Open an Excel File in .net

Dim xlApp As Microsoft.Office.Interop.Excel.Application
Dim xlWorkBook As Microsoft.Office.Interop.Excel.Workbook
Dim xlWorkSheet As Microsoft.Office.Interop.Excel.Worksheet
xlApp = New Microsoft.Office.Interop.Excel.ApplicationClass
xlWorkBook = xlApp.Workbooks.Open(strpath)
xlWorkSheet = xlWorkBook.Worksheets("sheet1")
xlWorkBook.Application.Visible = True