在DataGrid中使用DropDownList（原创）

  B/S架构的MIS中，在DataGrid中使用DropDownList是很常见的事情
Html代码如下：

< asp:TemplateColumn HeaderText = " 细目 " >

        < HeaderStyle Width = " 15% " ></ HeaderStyle >

               < ItemTemplate >

                      < asp:Label Runat = server Text = ' <%#DataBinder.Eval(Container, "DataItem.TicketType")%> ' ></ asp:Label >

               </ ItemTemplate >

        < EditItemTemplate >

                      < asp:DropDownList id = " ddl_Detail "  runat = " server "  Width = " 100% " >

                             < asp:ListItem Value = " Train " > 火车票 </ asp:ListItem >                                                   < asp:ListItem Value = " Air " > 机票 </ asp:ListItem >

                             < asp:ListItem Value = " Taxi " > 计程车费 </ asp:ListItem >

                             < asp:ListItem Value = " Bus " > 公共汽车费 </ asp:ListItem >

                             < asp:ListItem Value = " Book " > 订票费 </ asp:ListItem >

                             < asp:ListItem Value = " Other " > 其它 </ asp:ListItem >

                      </ asp:DropDownList >

                      < asp:Label Runat = server ID = lbl_Detail Text = ' <%#DataBinder.Eval(Container, "DataItem.TicketType")%> '  Visible = False ></ asp:Label >

        </ EditItemTemplate >

</ asp:TemplateColumn >

        < asp:TemplateColumn HeaderText = " 来程/去程 " >

          < HeaderStyle Width = " 15% " ></ HeaderStyle >

            < ItemTemplate >

                 < asp:Label Runat = server Text = ' <%#DataBinder.Eval(Container, "DataItem.ComeOrBack")%> ' ></ asp:Label >

               </ ItemTemplate >

        < EditItemTemplate >

               < asp:DropDownList id = " ddl_ComeOrBack "  runat = " server "  Width = " 100% " >

                      < asp:ListItem Value = " Come " > 来程 </ asp:ListItem >

                      < asp:ListItem Value = " Back " > 去程 </ asp:ListItem >

               </ asp:DropDownList >

               < asp:Label Runat = server ID = " lbl_ComeOrBack "  Text = ' <%#DataBinder.Eval(Container, "DataItem.ComeOrBack")%> '  Visible = False ></ asp:Label >

        </ EditItemTemplate >

</ asp:TemplateColumn >

这个DataGrid的第一个Column是编辑列,DropDownList放在EditItemTemplate里，点击“修改”，问题出现了，修改前的细目是“计程车票”，点击“编辑”后，如何使ddl的index还保持在继承车票上呢？C#代码如下：

private   void  dg_Detail_ItemDataBound( object  sender, System.Web.UI.WebControls.DataGridItemEventArgs e)

          {

              if( e.Item.ItemType == ListItemType.EditItem )//判断是否是EditItemTemplate

              {

                   DropDownList ddl_Detail = (DropDownList)e.Item.FindControl("ddl_Detail");

                   DropDownList ddl_ComeOrBack = (DropDownList)e.Item.FindControl("ddl_ComeOrBack");

                   Label lbl_Detail = (Label)e.Item.FindControl("lbl_Detail");

                   Label lbl_ComeOrBack = (Label)e.Item.FindControl("lbl_ComeOrBack");

 

                   string str1 = lbl_Detail.Text;

                   string str2 = lbl_ComeOrBack.Text;

                   ddl_Detail.SelectedIndex = ddl_Detail.Items.IndexOf( ddl_Detail.Items.FindByText(str1) );               ddl_ComeOrBack.SelectedIndex = ddl_ComeOrBack.Items.IndexOf( ddl_ComeOrBack.Items.FindByText(str2) );//这里的代码就是为了设置ddl的索引

              }        

         }

 OK啦!