使用语句和实体框架实体

I'm having a bit of trouble getting my head around when entities are attached and change tracked and when they are not. Sorry if this has already been asked. Say I have some code like this:

当附加实体并更改跟踪以及不实时跟踪时,我遇到了一些麻烦。对不起,如果已经问过这个问题。说我有这样的代码:

public MyEntity GetEntity()
{
    using (var ctx = new MyObjectContext)
    {
        return ctx.MyEntitySet.First();
    }
}

Then I call it

然后我打电话给它

var result = GetEntity();

Should result be attached or detached from the context?

结果应该与上下文相关联还是脱离?

I was under the impression that when the ObjectContext got disposed the entity lost its change tracking. Or is the Context never getting disposed.

我的印象是,当ObjectContext被处置时,实体失去了它的变化跟踪。或者上下文永远不会被处理掉。

2 个解决方案

#1

If you write that code while the ctx has been disposed, because you didn't detach the entity from the ctx you can't attach it to another context. Essentially there remains a backpointer from the Entity to the ctx, which stops that from happening.

如果在处理ctx时编写该代码,因为您没有从ctx中分离实体,则无法将其附加到其他上下文。从本质上讲,仍然有一个从实体到ctx的backpointer,它阻止了这种情况的发生。

I suppose you could say it is 'psuedo-attached'.

我想你可以说它是'假装的'。

Hope this helps

希望这可以帮助

Alex James

Program Manager Entity Framework Team

项目经理实体框架小组

#2

The attachment of the object isn't directly related to the context in my understanding. I believe that if the entity keys are set then it is still attached. You can detach the object, but you have to do it manually using the Detach method.

对象的附件与我理解的上下文没有直接关系。我相信如果设置了实体键,那么它仍然是附加的。您可以分离对象,但必须使用Detach方法手动执行此操作。

If you're after a detached object, try detaching it manually. Otherwise what you have done should allow you to update the object and save the changes without re-attaching the object.

如果您正在处理分离的对象,请尝试手动分离它。否则,您所做的事情应该允许您更新对象并保存更改,而无需重新附加对象。

Cheers

#1