Check-box template column loses status after paging

[Ed]

This must be very simple, so I assume I am at fault for not knowing how to do it!

I have a RadGrid with a check-box (not populated from the data-source) as follows:

<telerik:RadGrid ID="rgYoungWeber" runat="server" AllowSorting="true" AllowPaging="true" PagerStyle-Position="Top" DataSourceID="sdsYoungWeber" AutoGenerateColumns="false">
  <MasterTableView>
    <Columns>
      <telerik:GridBoundColumn DataField="Year" HeaderText="Year"></telerik:GridBoundColumn>
      <telerik:GridTemplateColumn>
        <ItemTemplate><asp:CheckBox id="cb" runat="server" /></ItemTemplate>
      </telerik:GridTemplateColumn>
    </Columns>
  </MasterTableView>
</telerik:RadGrid>

I want to be able to select certain items for printing by ticking the relevant boxes.  I can tick the boxes perfectly well but if I change page and then come back again, the ticks are removed.  How can I enable them to retain their state?  I am using a RadAjaxManagerProxy on the page (with a RadAjaxManager in the corresponding master-page) for partial post-backs: I have tried removing this but the check-boxes still lose their state after paging.

I am using Telerik DLL 2010.2.713.40 under Windows Server 2008.

All answers gratefully received,

Ed Graham

[Princy]

Hello Ed,

You can do the following to achieve this.

1. Add an 'OnCheckedChanged' event handler to the CheckBox .
   
2. When the CheckBox in checked, store the key values for the selected row in a Session variable.
3. When the CheckBox is unchecked, remove the key values from the Session variable.
4. Add a PreRender event handler to the grid.
5. In the pre-render event of the grid, traverse the rows of the grid and compare their key values to the values saved in the Session variable. Whenever you find a match, check the corresponding Checkbox.

You can refer the following documentation which explains how to persist the selected rows server-side on sorting/paging/filtering/grouping. Use the same logic and make necessary modification.
Persisting the selected rows server-side on sorting/paging/filtering/grouping

Thanks,
Princy.

[Ed]

Thanks a lot, Princy -- that worked nicely.  I have to say I'm surprised it's so complicated, though; surely this is what most people would assume should be the default behaviour, isn't it?  I must be missing something ...

[JJ]

Got it. Thanks! 

 

 

 

 

[Allen]

Is there a working example of this for WPF?