Displaying Total in Footer of GridView and also Add Sum of columns(row vise) in last Column

Question

In my Asp.net App, i have a GridView and i generate the data of column[6] by myself using code behind.

by looking at the code below, i have

Answer 1

protected void gvBill_RowDataBound(object sender, GridViewRowEventArgs e)
    {

        if (e.Row.RowType == DataControlRowType.DataRow)

            Total += Convert.ToDecimal(DataBinder.Eval(e.Row.DataItem, "InvMstAmount"));
        else if (e.Row.RowType == DataControlRowType.Footer)

            e.Row.Cells[7].Text = String.Format("{0:0}", "" + Total + "");
    }