Easily Retrieve the Foreign Key from an Entity Framework Entity

Retrieving the foreign key from a related entity in the Entity Framework (3.5 SP1) is not very easy. Below is an extension method you can add to make it simple:

public static int ForeignKey(this EntityReference entRef)
{
  int keyval = 0;

  if (int.TryParse(entRef.EntityKey.EntityKeyValues[0].Value.ToString(), 
       out keyval))
  {
    return keyval;
  }
  else
  {
    return 0;
  }
}

Usage:

var key = person.AddressReference.ForeignKey();

Tip By: David McCarter