Maintain viewstate with controls in CommandItemTemplate

[Michael Gois]

I have a RadGrid with a custom CommandItemTemplate which contains a checkbox within it. The data which is displayed in the grid is dependent on whether the checkbox is checked or not, which means that in the onCheckChanged handler for the checkbox, I must call the grid.Rebind() method. The problem however is that whenever I call the rebind method, the checkbox resets its state back to unchecked.

Here is the ASPX code:

        <telerik:RadGrid ID="RadGrid1" runat="server" OnNeedDataSource="RadGrid1_NeedDataSource"
            Skin="Vista" Width="287px">
            <mastertableview autogeneratecolumns="False" commanditemdisplay="Top">
<Columns>
<telerik:GridBoundColumn DataField="ID" EmptyDataText="&amp;nbsp;" HeaderText="ID" UniqueName="ID"></telerik:GridBoundColumn>
</Columns>
<CommandItemTemplate>
<asp:CheckBox id="chkShowExistingMappings" runat="server" Text="Show nodes with existing mappings" AutoPostBack="True" Width="237px" __designer:wfdid="w26" OnCheckedChanged="chkShowExistingMappings_CheckedChanged"></asp:CheckBox>
</CommandItemTemplate>
</mastertableview>
        </telerik:RadGrid>

And here is the code behind:

protected DataTable GetData()
    {
        DataTable table = new DataTable();
        table.Columns.Add("ID", typeof(int));
        table.Columns.Add("Product", typeof(string));
        table.Columns.Add("MinPrice", typeof(double));
        table.Columns.Add("Price", typeof(double));
        table.Rows.Add(1, "Tea", 1.00, 1.32);
        table.Rows.Add(2, "Chocolate", 4.00, 4.70);
        table.Rows.Add(3, "Cookies", 2.50, 3.06);
        return table;
    }

    protected void RadGrid1_NeedDataSource(object source, Telerik.Web.UI.GridNeedDataSourceEventArgs e)
    {
        RadGrid1.DataSource = GetData();
    }

    protected void chkShowExistingMappings_CheckedChanged(object sender, EventArgs e)
    {
        RadGrid1.Rebind();
    }

If you run it and tick the checkbox, you will see that it doesnt maintain its checked state. Can anyone tell me how to get this working please?
Thanks

[Princy]

Hello Michael,

To persist the checkbox state on postbacks, you can go through the following help link. You can modify the code according to your requirements.
Persisting CheckBox control state in GridTemplateColumn on rebind

Thanks
Princy.

[Michael Gois]

Thanks Princy,
Managed to sort it out now with help from that link. Just had to modify the code slightly in Grid_DataBinding to check if e.Item is GridCommandItem rather than GridEditFormItem.