我试图让Department
对象的Studies
属性延迟加载,但它只会在我急切加载时加载。我已将DepartmentId
添加到Study
级别,但没有结果,使用了ICollection
,ISet
和virtual
。公共和私人的制定者似乎没有什么区别(也不应该)。似乎没有任何工作。使用EF 6.1。实体框架急切加载关联的集合,但不会延迟加载它
public class Department
{
private Department() {}
public Department(DepartmentTitle title)
{
if (title == null) throw new ArgumentNullException();
this.Title = title;
this.Studies = new HashSet<Study>();
}
public int DepartmentId { get; private set; }
public virtual DepartmentTitle Title { get; private set; }
public virtual ICollection<Study> Studies { get; set; }
}
public class Study
{
private Study() {}
public Study(StudyTitle title, Department department)
{
if (title == null) throw new ArgumentNullException();
if (department == null) throw new ArgumentNullException();
this.Title = title;
this.Department = department;
}
public int StudyId { get; private set; }
public virtual StudyTitle Title { get; private set; }
public virtual Department Department { get; set; }
}
// Here I save the department and study objects
// I verified they exist in the database
var department = new Department(new DepartmentTitle("Department Title Here"));
department.Studies.Add(new Study(new StudyTitle("Study Title Here"), department));
data.SaveChanges();
// In a new database context
// Here I try to lazy load the Studies property, but get null
// It works if I add Include("Studies") before Where()
Department department = data.Departments.Where(d => d.Title.Value == "Department Title Here").Single();
System.Console.WriteLine(department.Studies.First().Title.Value);
// DepartmentTitle and StudyTitle are simple complex types with a Value property
这很奇怪,但它的工作原理。我认为它没有什么区别,因为它告诉我们EF如何使用反射来访问任何需要的东西。显然不是。 – Seralize
我希望在几个星期前我偶然发现了这个问题。试图弄清楚为什么懒加载不适用于我的实体。我在我的实体上有一个私有的无参数构造函数,它可以很好地与EF一起从数据库加载实体。将其更改为受保护,并延迟加载最终有效。 !AARGH – TheOtherTimDuncan