EntityKey Class

using (AdventureWorksEntities advWorksContext =
    new AdventureWorksEntities())
{
    try
    {
        Object entity = null;
        IEnumerable<KeyValuePair<string, object>> entityKeyValues =
            new KeyValuePair<string, object>[] {
                new KeyValuePair<string, object>("SalesOrderID", 43680) };

        // Create the  key for a specific SalesOrderHeader object. 
        EntityKey key = new EntityKey("AdventureWorksEntities.SalesOrderHeader", entityKeyValues);

        // Get the object from the context or the persisted store by its key. 
        if (advWorksContext.TryGetObjectByKey(key, out entity))
        {
            Console.WriteLine("The requested " + entity.GetType().FullName + 
                " object was found");
        }
        else
        {
            Console.WriteLine("An object with this key " +
                "could not be found.");
        }
    }
    catch (EntitySqlException ex)
    {
        Console.WriteLine(ex.ToString());
    }
}