System.IndexOutOfRangeException：找不到列

dtView.Sort = strSort;

protected void SortGridData_Hkl(Object sender, GridViewSortEventArgs e)
    {
        GridView _dgd_work_onoff = (GridView)Page.FindControl(\"bodyuc$dgd_work_onoff\");
        DataSet dstemp;
        DataView dtView;
        if (ViewState[\"dsfetchResults\"] != null)
        {
            dstemp = (DataSet)ViewState[\"dsfetchResults\"];
            string strSortOrder = ViewState[\"SortOrder\"].ToString();

            if (strSortOrder == \"DESC\")
            {
                strSortOrder = \"ASC\";
                ViewState[\"SortOrder\"] = strSortOrder;
            }
            else
            {
                strSortOrder = \"DESC\";
                ViewState[\"SortOrder\"] = strSortOrder;
            }

            string strSort = e.SortExpression.ToString() + \" \" + strSortOrder;
            ViewState[\"SortString\"] = strSort;

            dtView = dstemp.Tables[0].DefaultView;

            dtView.Sort = strSort;
            if (dtView.Count != 0)
            {
                if (_dgd_work_onoff != null)
                {
                    _dgd_work_onoff.DataSource = dtView;
                    _dgd_work_onoff.DataBind();
                }
            }


        }