EF+WCF怎样更新数据?

public virtual void Update(T entity)
        {
            T current = this.Where(m => m.Id.Equals(entity.Id))
                     .SingleOrDefault();
            if (current != null)
            {
                var context = ((IObjectContextAdapter)DbContext).ObjectContext;
                ObjectStateEntry objectStateEntry;
                if (context.ObjectStateManager.TryGetObjectStateEntry(current, out objectStateEntry))
                {
                    objectStateEntry.ApplyCurrentValues(entity);
                    objectStateEntry.SetModified();
                    this.Commit();
                }
            }
        }