How to export my Grid to Excel with Password proteced

Question

I have a code but got error.plz help me

Excel.Application xlApp;

Excel.Workbook xlWorkBook;

Excel.Worksheet xlWorkSheet;

object misValue = System.Reflection.Missing.Value;

xlApp = new Excel.Application();

xlWorkBook = xlApp.Workbooks.Add(misValue);

xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);

int CCol = 1;

for (int j = 1; j <= dgcBankSetup.Columns.Count; j++)

{

xlWorkSheet.Cells[1, CCol] = dgcBankSetup.Columns[j].Header;

xlWorkSheet.Cells[1, CCol].ColumnWidth = dgcBankSetup.Columns[j].Width;

xlWorkSheet.Cells[1, CCol].Font.Bold = true;

CCol = CCol + 1;

}

foreach (DataRowView i in dgcBankSetup.ItemsSource)

{

DataRow DR = i.Row;

CCol = 1;

for (int j = 1; j <= dgcBankSetup.Columns.Count; j++)

{

xlWorkSheet.Cells[i, CCol].value = dgcBankSetup.rows

//gcBankSetup.SelectAllCells();

CCol = CCol + 1;

}

}

xlWorkSheet.Cells.Borders.LineStyle = 1;

xlWorkBook.SaveAs(SaveDialogBox.FileName, Excel.XlFileFormat.xlWorkbookNormal, misValue, misValue, misValue, misValue, Excel.XlSaveAsAccessMode.xlExclusive, misValue, misValue, misValue, misValue, misValue);

xlWorkBook.Close(true, misValue, misValue);

xlApp.Quit();

releaseObject(xlWorkSheet);

releaseObject(xlWorkBook);

releaseObject(xlApp);