How to display data from a related table for a column

[Hector]

This seems to be a simple solution, but I cannot find it.  I am using LinqToSQL DomainService and I have with a simple table with a column that points to a look-up table.  When I define the columns for the GridView, I tried binding to Address.StateName and nothing displays.  Here is an example of what I need...
Example:
Table:
Address                
========
Address1
Address2
City
State
Zip

Table:
States
=======
StateCode
StateName

In my gridview, I would like to display the StateName, not the StateCode

Thanks.

[Karlkim Suwanmongkol]

I had a similar problem. And what I did was to write the ValueConverter for that column.

public class StateCodeToNameConverter : IValueConverter
    {

        #region IValueConverter Members

        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            if (value == null)
                return null;

            if(value.GetType() != typeof(string))
                throw new ArgumentException();

            if (t != null){
                // find the full state name and return;
}

            return null;
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }

        #endregion
    }

[Hector]

Thank you Karlkim for your suggestion.
I actually found out what the problem was.  Since I am using Linq to SQL DomainService, as default does not return the related entities.  I found out I had to modify the DomainService metadata and where I set up the data context. 
To the DomainServiceMetadata, I added the [Include] attribute on the enteties I wanted returned
DomainServiceMetadata.cs:

// The MetadataTypeAttribute identifies RTNType_LUMetadata as the class
    // that carries additional metadata for the RTNType_LU class.
    [MetadataTypeAttribute(typeof(RTNType_LU.RTNType_LUMetadata))]
    public partial class RTNType_LU
    {

        // This class allows you to attach custom attributes to properties
        // of the RTNType_LU class.
        //
        // For example, the following marks the Xyz property as a
        // required field and specifies the format for valid values:
        //    [Required]
        //    [RegularExpression("[A-Z][A-Za-z0-9]*")]
        //    [StringLength(32)]
        //    public string Xyz;
        internal sealed class RTNType_LUMetadata
        {

            // Metadata classes are not meant to be instantiated.
            private RTNType_LUMetadata()
            {
            }

            public string Description;

            public int ID;
            [Include]
            public EntitySet<RTN> RTNs;
        }
    }

Then on the Context call, I added this LoadOptions:
DomainService.cs:

public IQueryable<RTN> GetRTNs()
        {
            //In your DataContext Setup you need to specify the load options:
            System.Data.Linq.DataLoadOptions options = new System.Data.Linq.DataLoadOptions();
            options.LoadWith<RTN>(p => p.RTN_Marketings);
            options.LoadWith<RTN>(R => R.RTNType_LU);
            Context.LoadOptions = options;
            return this.Context.RTNs;
        }

This LoadOptions is only for Linq To Sql, but for Entity Framework, it is something like:

public Person GetPersonById(long Id)
{
    return this.Context.People.Include("Address").Where(p => p.Id == Id).FirstOrDefault();
}

So now, my Net Ria calls are returning the associated elements and now I can do this on my RadGridView Columns defenintion:

<telerikGridView:RadGridView.Columns>
     <telerikGridView:GridViewDataColumn Header="RTN" DataMemberBinding="{Binding Type_LU.Description}" />
</telerikGridView:RadGridView.Columns>