RadGrid Sorting with IList<T> with object composition

[Troy]

Hi,
I'm using an IList<T> of complex objects that are composed of other complex objects as properties.  I can get the RadGrid to sort ok on a regular property of type string.  But when I try to sort on a property that contains another business object, I get this error:

At least one object must implement IComparable.

This is what my code looks like:

<telerik:GridBoundColumn DataField="BatchNumber" HeaderText="Batch Number" SortExpression="BatchNumber" />

<telerik:GridTemplateColumn HeaderText="Client" SortExpression="Client">                   
     <ItemTemplate><%# (((Batch)Container.DataItem).Client).Name %>
     </ItemTemplate>
</telerik:GridTemplateColumn>

The blue property works fine.  I can't figure out what should go in the SortExpression property to show I want the Name property from the Client object to determine my sorting.

Thanks!
Troy

[Troy]

Nevermind on the first issue I described.  I just found syntax for using a regular GridBoundColumn for composed objects.  The sorting works now, except for columns that have a row with a null object as a property.  I get a null reference error now just on the sorting, but not the initial binding.  Is there a way to get the sorting mechanism to ignore the null object?

Thanks,
Troy

[Sebastian]

Hello Troy,

Basically, sorting with nullable objects should be supported by the sorting mechanism of RadGrid as shown in this online demo of the product:

http://demos.telerik.com/ASPNET/Prometheus/Grid/Examples/Programming/Binding/DefaultCS.aspx

Please compare your code implementation with the one presented in the demo and outline the differences - they can help us track down the reason for the error to eliminate it.

Best regards,
Stephen
the Telerik team

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[Troy]

The nullable type would be ok, but I'm not using primative types (datetime or int) to use nullable.  I have a custom object with a property as another custom type.  Code is below:

public class Batch
    {
       
        public Batch (string batchNumber, User batchOwner)
        {           
            BatchNumber = batchNumber;           
            BatchOwner = batchOwner;
        }
             
        public virtual string BatchNumber { get; set; }      
        public virtual User BatchOwner { get; set; }
        public virtual User BatchProofer { get; set; }      
    }

As you can see, the BatchProofer property can be null, and that is what is causing the problems on sorting.  I can't make a nullable User type for the property.

Thanks.
Troy

[Rosen]

Hello Troy,

Unfortunately, RadGrid does not support binding to properties of types different then primitive datatypes. Please refer to our help documentation for a list of supported types here.

Best wishes,
Rosen
the Telerik team

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