DataGrid排序中加入方向标识核心代碼

在DataGrid中根據排序方向,在HeaderText加入排序方向.代碼如下:

  /// <summary>
    /// 得到數據,根據分頁Index及排序ID綁定數據
    /// </summary>
    /// <param name="iPageIndex">頁碼</param>
    /// <param name="sSortID">排序的ID</param>
    private void Copmmon(int iPageIndex,string sSortID)
    {        
        string sDeptID = Request.QueryString["strDeptID"];
        string sQuery = "select UioID,UioName from Hp_UserInfo where UioDeptID='{0}'";
        sQuery = string.Format(sQuery, sDeptID);
        if (!string.IsNullOrEmpty(sSortID) && sSortID != "")
        {
            string sSortDirection = "DESC"; //为排序方向变量赋初值
            if (sSortDirection == grdRequireList.Attributes["GrdSortDirection"])
            {
                //获得下一次的排序状态
                sSortDirection = (grdRequireList.Attributes["GrdSortDirection"].ToString() == sSortDirection ? "ASC" : "DESC");
            }
            grdRequireList.Attributes["GrdSortDirection"] = sSortDirection;
            string sOrder = " Order by {0} {1}";
            sOrder = string.Format(sOrder, sSortID, sSortDirection);
            sQuery = sQuery + sOrder;

            //排序图标
            char[] cArray = new char[] { '↑', '↓' };
            //加方向标
            for (int iSor = 0; iSor < grdRequireList.Columns.Count; iSor++)
            {
                if (grdRequireList.Columns[iSor].SortExpression.ToString() == sSortID)
                {
                    int iColindex = iSor;
                    if (sSortDirection=="DESC")
                    {
                        grdRequireList.Columns[iSor].HeaderText = grdRequireList.Columns[iSor].HeaderText.Trim(cArray);
                        grdRequireList.Columns[iColindex].HeaderText = grdRequireList.Columns[iColindex].HeaderText + "↓";
                    }
                    else
                    {
                        grdRequireList.Columns[iSor].HeaderText = grdRequireList.Columns[iSor].HeaderText.Trim(cArray);
                        grdRequireList.Columns[iColindex].HeaderText = grdRequireList.Columns[iColindex].HeaderText + "↑";
                    }
                   
                }
                else
                {
                    grdRequireList.Columns[iSor].HeaderText = grdRequireList.Columns[iSor].HeaderText.Trim(cArray);
                }
            }
        }       

        DataView dvApplyers = TDAIClient.BusinessDB.GetDataView(sQuery);
        if (dvApplyers.Count > 0)
        {
            //执行查询
            grdRequireList.PageSize = 500;
            grdRequireList.DataSource = dvApplyers;
            grdRequireList.CurrentPageIndex = iPageIndex;
            grdRequireList.DataBind();
        }
    }