在什么情况下是由必要的事件分离？ [英] In what cases are detaching from events necessary?
问题描述
我不知道如果我在对象连接到事件的影响完全清楚
I'm not sure if I'm entirely clear on the implications of attaching to events in objects.
这是我目前的理解，正确的或阐述：
This is my current understanding, correct or elaborate:
1。连接到局部类事件并不需要被分离
例如：
this.Closing + =新System.ComponentModel.CancelEventHandler（MainWindow_Closing）;
公共事件的EventHandler OnMyCustomEvent =代表{};
我假设，当你的对象被处置，或者垃圾回收，该功能被释放，并会自动分离的事件。
I'm assuming that when your object is disposed or garbage collected, the functions are deallocated and would automatically detach from the events.
2。附加到对象不再需要（= NULL;），已经被从
例子分离：
连接到一个计时器经过的事件，这你只响应一次。我会假设你需要定时器存储在一个局部变量，因此您可以在事件触发后脱落经过事件。因此，在本地方法范围宣布计时器像这样将导致泄漏：
Examples: Attaching to a timer's Elapsed event, which you only respond to once. I would assume you need to store the Timer in a local variable so you can detached the Elapsed event after the event fires. Thus, declaring the timer in a local method scope like so would result in a leak:
System.Timers.Timer myDataTimer =新System.Timers .Timer（1000）;
myDataTimer.Elapsed + =新System.Timers.ElapsedEventHandler（myDataTimer_Elapsed）;
3。附加到事件在本地对象类不需要处理？
例如，如果你有你的创建，监控一个ObservableCollection，并让死。如果您使用的是本地的，私有的功能附加到CollectionChanged事件，不会此功能解除分配当你的类垃圾回收，造成的ObservableCollection也被释放？
For example, if you had an ObservableCollection that your creates, monitors, and lets die. If you attached to the CollectionChanged event using a local, private function, wouldn't this function deallocate when your class is garbage collected, causing the ObservableCollection to also be freed?
我敢肯定，我已经在那里我已经使用对象停了下来，未能从事件分离（例如定时器比如我做了）的地方，所以我在寻找的是如何工作的更清楚的解释。
I'm sure I have places where I've stopped using objects and have failed to detach from an event (for example, the timer example I made), so I'm looking for a clearer explanation on how this works.
推荐答案
我觉得你让复杂得多，它需要的。你只需要记住两件事情：
I think you're making it more complicated than it needs to be. You just need to remember two things:
- 当您订阅事件，该事件的所有者（发布者）一般保持一个参考到委托你订阅用。
- 如果您使用实例方法为代表的动作，然后委托有它的目标对象的引用。
这意味着，如果你写的：
This means that if you write:
publisher.SomeEvent += subscriber.SomeMethod;
然后用户将没有资格垃圾收集之前出版商是，除非你以后退订。
Then subscriber won't be eligible for garbage collection before publisher is unless you unsubscribe later.
请注意，在许多情况下，用户就是这个：
Note that in many cases, subscriber is just this:
publisher.SomeEvent += myDataTimer_Elapsed;
等同于：
is equivalent to:
publisher.SomeEvent += this.myDataTimer_Elapsed;
假设它是一个实例方法。
assuming it's an instance method.
还有的只是由于事件订阅没有的反向关系 - 换言之，用户不守活出版商
There is no reverse relationship just due to event subscription - in other words the subscriber doesn't keep the publisher alive.
请参阅的我的文章对事件和委托了解更多信息，顺便说一句。
See my article on events and delegates for more information, by the way.
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