Binding to property of property of object collection

[TS]

when binding to a datagrid for example, is it possible to use databinding
syntax to bind to a property of a property? Say the datasource="Cars" which
is a collection of car classes and the DataValueField = "Driver.Name" which
is the Car.Driver property and then the Driver.Name property.

thanks

 

[KJ]

Yes, this is possible. In fact, in .NET 2.0, this is one of the main
purposes of the ObjectDataSource control. When binding an object in a
DataGrid (.NET 1.x) using databinding syntax, you can do as follows (in
the example, the datasource is an ArrayList of Chapter objects, of
which WorkItem is a property of each Chapter):

<asp:TemplateColumn HeaderText="Last Change Date">
<ItemTemplate>
<asp:Label id="lblStatusDate" runat="server">
<%# DataBinder.Eval(Container.DataItem,
"WorkItem.Status.LastChangeDate", "{0:d}") %>
</asp:Label>
</ItemTemplate>
</asp:TemplateColumn>

 

[Walter Wang [MSFT]]

Hi TS,

Based on the interaction between the data source and the control, you can
identify three distinct forms of data binding and, subsequently, data-bound
controls--simple binding, list controls, and complex binding.

"DataValueField" belongs to the list controls. Internally it uses
DataBinder.GetPropertyValue to get bound data. And currently this function
doesn't support property path, it can only retrieve the property of the
data source.

As KJ pointed out, DataBinder.Eval can evaluate using the property path,
it's used by complex binding which is also demonstrated by KJ's code.

Hope this helps. Please feel free to post here if anything is unclear.


Sincerely,
Walter Wang ([email protected], remove 'online.')
Microsoft Online Community Support

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[TS]

thanks KJ!!!
I thought i had seen it done but have had issues with it before.