每个数据列表行中的UpdatePanel

Question

I am trying to update each DataList row without having to PostBack the entire DataList.

Basically I want to go with

<DataList>
   <ItemTemplate>
      <UpdatePanel>
      </UpdatePanel>
   </ItemTemplate>
</DataList>

instead of

<UpdatePanel>
   <DataList>
      <ItemTemplate>
      </ItemTemplate>
   </DataList>
</UpdatePanel>

Is this possible, or better - does it make any sense?

Answer 1

Yes , It is possible, I personally do that in some situation.

But you must be aware that with an UpdatePanel is not a perfect solution. As an example, the client sent the complete ViewState of the page. So there will be a gain, but not as big as you might expect.

I suggest you to read the UpdatePanel Considerations section in this link for more information.

Update :

You must also watch how you setup you template, example : you cannot put a table row in a update panel.

Don't do this :

<asp:DataList>
   <HeaderTemplate>
      <Table>
   </HeaderTemplate>

   <ItemTemplate>
     <UpdatePanel>
         <tr>
             <td>...</td>
             <td>...</td>
         </tr>
     </UpdatePanel>
   </ItemTemplate>
   <FooterTemplate>
      </Table>
   </FooterTemplate>
</asp:DataList>

But you cant do :

<asp:DataList>
   <HeaderTemplate>
      <Table>
   </HeaderTemplate>

   <ItemTemplate>
     <UpdatePanel>
     <tr>
         <td>
             <UpdatePanel>
                ...
             </UpdatePanel>
         </td>
     </tr>
   </ItemTemplate>
   <FooterTemplate>
      </Table>
   </FooterTemplate>
</asp:DataList>