GridView data collection Code

  protected void gviewEmployees_RowDataBound(object sender, GridViewRowEventArgs e)
    {

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

            e.Row.Attributes.Add("onmouseout", "this.style.backgroundColor=\"\"");
            e.Row.Attributes.Add("onmouseover", "this.style.backgroundColor=\"#BFDFFF\"");

            TextBox txt = (TextBox)e.Row.Cells[3].FindControl("txtOrderNum");
            SumConsume += Convert.ToSingle(e.Row.Cells[2].Text.ToString().Substring(1)) * Convert.ToSingle(txt.Text);

        }
        IF (e.Row.RowType == DataControlRowType.Footer)
        {
            e.Row.Cells [. 4] .Text = "Your total consumption:" + string.Format ( "{0 : C}", Convert.ToDecimal (SumConsume.ToString ()));
        }
    }

Reproduced in: https: //www.cnblogs.com/zhangchenliang/archive/2008/01/08/1029669.html