我曾经看过一些书(例如编程entity framework代码第一个Julia Lerman )定义了他们的领域类(POCO),没有像以下导航属性的初始化: public class User { public int Id { get; set; } public string UserName { get; set; } public virtual ICollection<Address> Address { get; set; } public virtual License License { get; set; } } 一些其他书籍或工具(例如Entity Framework Power Tools )在生成POCO时会初始化该类的导航属性,如: public class User { public User() { this.Addresses = new IList<Address>(); […]