ASP.NET GridView排序升序标题样式不起作用

Question

我的SortedAscendingHeaderStyle和SortedDescendingHeaderStyle根本不起作用

<asp:GridView ID="grdProducts" runat="server" CssClass="grid" AllowPaging="True" AllowSorting="True" PageSize="100" EmptyDataText="No data to show"
              onrowdatabound="grdProducts_RowDataBound"  onrowediting="grdProducts_RowEditing" onsorting="grdProducts_Sorting" AutoGenerateEditButton="True">
  <AlternatingRowStyle CssClass="even" />
  <SortedAscendingHeaderStyle ForeColor="White" CssClass="sorted" />
  <SortedDescendingHeaderStyle CssClass="sorted desc" />
</asp:GridView>

单击标题时，行已正确排序，但是当我使用FireBug检查标题时，它仅显示:(这是升序排列的)

<th scope="col">
  <a href="javascript:__doPostBack('ctl00$body$ctl00$grdProducts','Sort$Namekey')">Namekey</a>
</th>

根本没有设置ForeColor和CssClass。

有人知道我在做什么错吗？

编辑:我的C#代码背后

  protected void grdProducts_Sorting(object sender, GridViewSortEventArgs e)
  {
    if ((string)ViewState["SortColumn"] == e.SortExpression)
      ViewState["SortDirection"] = ((string)ViewState["SortDirection"] == "") ? " DESC" : "";
    else
    {
      ViewState["SortColumn"] = e.SortExpression;
      ViewState["SortDirection"] = "";
    }
  }

  protected override void OnPreRender(EventArgs e)
  {
    BindGrid();
    base.OnPreRender(e);
  }

  private void BindGrid()
  {
    string query = "SELECT ... ORDER BY " + ViewState["SortColumn"] + ViewState["SortDirection"];

    DataTable dt = SqlFunctions.Select(query);
    grdProducts.DataSource = dt;
    grdProducts.DataBind();
  }

Answer 1

如果您不使用asp:SQLDataSource作为GridView数据源，则不确定 SortedDescendingHeaderStyle 是否可以在没有代码的情况下工作。但是，只需编写一些代码，您就可以到达那里。

您需要将CSS样式手动应用于标题单元格。您可以在“排序”事件中执行此操作。

protected void grdProducts_Sorting(object sender, GridViewSortEventArgs e)
{
   if ((string)ViewState["SortColumn"] == e.SortExpression)
   {
      ViewState["SortDirection"] = ((string)ViewState["SortDirection"] == "") ? " DESC" : "";
      grdProducts.HeaderRow.Cells[GetColumnIndex( e.SortExpression )].CssClass = "AscendingHeaderStyle";
   }
   else
   {
      ViewState["SortColumn"] = e.SortExpression;
      ViewState["SortDirection"] = "";
      grdProducts.HeaderRow.Cells[GetColumnIndex( e.SortExpression )].CssClass = "DescendingHeaderStyle";
   }
   BindGrid();
}




private int GetColumnIndex( string SortExpression )
{
    int i = 0;
    foreach( DataControlField c in gvwCustomers.Columns )
    {
        if( c.SortExpression == SortExpression )
            break;
        i++;
    }
    return i;
}