Code First和EF 5.0未加载导航属性

Question

我试图通过Code First和EF 5.0加载导航属性子对象加载为null.下面是代码.

  [Table("ls_roles")]
    public class Role
    {
        [Required]
        [Key]
        public int RoleID { get; set; }

        [Required]
        public String BarColor { get; set; }

        [ForeignKey("RoleId")]
        public virtual ICollection<ScheduleEmployee> Employees { get; set; }
    }

    [Table("ls_ScheduleEmployee")]
    public class ScheduleEmployee
    {
        [Key]
        [Required]
        public int Id { get; set; }

        [Required]
        public int RoleId { get; set; }

        [ForeignKey("RoleId")]
        public  Role Role { get; set; }
    }

编辑:调用代码

class Program
{
    static void Main(string[] args)
    {
        var x = new Model.ContextEntityFramework().ScheduleEmployees.FirstOrDefault();
    }
}

x.Role ==此时为null

Answer 1

为了使延迟加载工作,应该将类的所有属性定义为虚拟.这是Entity Framework创建支持延迟加载的代理对象所必需的.

有关更多信息,请参见此处

Answer 2

您必须对您的主叫代码执行.include以包含子项.

就像是

Model.ContextEntityFramework().ScheduleEmployees.Include(x => x.Role).FirstOrDefault();