GridView bound with Properties of nested class

Question

I have an object map similar to what's listed below. When I try to bind the properties of NestedClass in a GridView I get the error:

"A field or property with the name 'NestedClass.Name' was not found on the selected data source."

The GridView is bound to an ObjectDataSource and the ObjectDataSource is bound to a fully populated instance of BoundClass.

Is there any way around this?

Sample classes:

public class BoundClass {     public string Name { get; set; }     public NestedClass NestedClass { get; set; } }  public class NestedClass {     public string Name { get; set; } } 

Answer 1

Only immediate properties of an instance can be displayed in a BoundField column.

One must instead use DataBinder.Eval in an itemtemplate to access the nested property instead of assigning it to a boundfield.

Example:

<asp:TemplateField>     <itemtemplate>         <p><%#DataBinder.Eval(Container.DataItem, "NestedClass.Name")%></p>     </itemtemplate> </asp:TemplateField> 

Alternatively, you can create a custom class which inherits BoundField and overrides GetValue to use DataBinder.Eval, as described in this blog post:

http://web.archive.org/web/20120121123301/http://iridescence.no/post/FixingBoundFieldSupportforCompositeObjects.aspx

Answer 2

This extension on BoundField calls DataBinder.Eval(), which does support nested properties:

public class BetterBoundField : BoundField {     protected override object GetValue(Control controlContainer)     {         if (DataField.Contains("."))         {             var component = DataBinder.GetDataItem(controlContainer);             return DataBinder.Eval(component, DataField);         }         return base.GetValue(controlContainer);     } }