Question

I have a DataGrid that looks like this (slightly simplified here):

<asp:DataGrid ID='grdQuotas' runat='server' AutoGenerateColumns='False'>     <HeaderStyle CssClass='quotas-header' />     <Columns>         <asp:TemplateColumn>             <HeaderTemplate>                 Max order level</HeaderTemplate>             <ItemTemplate>                 <asp:DropDownList ID='ddlMaxOrderLevel' runat='server' DataSourceID='xdsOrderLevel'                     DataTextField='Text' DataValueField='Value' SelectedValue='<%# Bind('MaxOrderLevel') %>'>                 </asp:DropDownList>             </ItemTemplate>         </asp:TemplateColumn>     </Columns> </asp:DataGrid>  <asp:XmlDataSource ID='xdsOrderLevel' runat='server' DataFile='~/App_Data/OrderLevels.xml'> </asp:XmlDataSource> 

In my Page_Load event handler I am creating a DataTable containing default values and DataBinding it to the DataGrid.

The problem is that this is taking place before the DropDownList ddlMaxOrderLevel has been bound to its DataSource, so I get a runtime error telling me that the SelectedValue cannot be set.

If ddlMaxOrderLevel was not in a DataGrid I could just call DataBind() on it. However I cannot do that in this scenario – since it is in an ItemTemplate.

Can anyone suggest a workaround or alternate approach?

Answer 1

Create another DataSource and bind it to the DataGrid. Where the SelectMethod would return the default values in a simple object.

Then all the binding should happily work together.