问题描述
我想知道为什么DbContext对象上没有Detach方法，就像ObjectContext一样。 我只能假设这个遗漏是有意的，但我很难搞清楚原因。 我需要能够分离并重新附加实体
（例如，用于放入ASP.NET项目中的缓存）。 但是，由于我无法分离实体，当我尝试附加与先前上下文关联的实体时，我得到"实体对象不能被多个实例引用
of IEntityChangeTracker "例外。
I'm wondering why there is no Detach method on the DbContext object like there is for ObjectContext. I can only assume this omission was intentional, but I have a hard time figuring out why. I need to be able to detach and re-attach entities (for putting in the cache in an ASP.NET project, for example). However, since I can't detach an entity, when I try to attach an entity that was associated with a previous context, I get the "An entity object cannot be referenced by multiple instances of IEntityChangeTracker" exception.
这里有什么指导？ 我错过了什么吗？
What's the guidance here? Am I missing something?
推荐答案
分离的能力将在下一个版本中可用（我们不希望在根DbSet级别公开它，因为它是一个更高级的操作）。
The ability to detach will be available in the next release (we didn't want to expose it at the root DbSet level because it is a more advanced operation).
在CTP4中你可以添加一个Detach方法如下;
In CTP4 you can add a Detach method as follows;
public class MyContext : DbContext
{
...
public void Detach(object entity)
{
this.ObjectContext.ObjectStateManager.ChangeObjectState(entity, EntityState.Detached);
}
}
~Rowan
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