Grid View Data Binder

 if (((GridViewRow)e.Row).RowType == DataControlRowType.Header) return;
        if (((GridViewRow)e.Row).RowType == DataControlRowType.Footer)
        {
            ((Label)((GridViewRow)e.Row).FindControl("lblDebit")).Text = viewStateLedgerBook.GroupBy(ledgerName => ledgerName.LedgerName).Select(ledgerName => ledgerName.First()).Sum(totalDebitAmount => totalDebitAmount.LedgerTotalDebitAmount).ToString();//1 Total Debit Amount
            ((Label)((GridViewRow)e.Row).FindControl("lblCredit")).Text = viewStateLedgerBook.GroupBy(ledgerName => ledgerName.LedgerName).Select(ledgerName => ledgerName.First()).Sum(totalCreditAmount => totalCreditAmount.LedgerTotalCreditAmount).ToString();//2 Total Credit Amount          
        }