注册在MVVM光一个视图模型之外的信息？ [英] Registering for messages outside of a ViewModel in MVVM Light?

问题描述

我想注册一个消息的视图模型之外的静态构造函数，但显然该注册并没有采取：已注册的动作绝然，当邮件被发送。我试图传递null或为收件人一个新的对象参数登记时，但没有奏效。

I was trying to register for a message outside of a ViewModel in a static constructor but apparently that registration didn't take: the registered action never ran when messages were sent. I tried passing in null or a new object for the recipient parameter when registering but that didn't work.

我有一种感觉，指定收件人必须是重要的莫名其妙，但我不知道为什么。我认为，所有收件人都应该接受广播消息呢。有没有一种方法，使这项工作，或者这根本不支持？

I have a feeling the specifying the recipient must be important somehow, but I don't know why. I thought that all recipients were supposed to get broadcasted messages anyway. Is there a way to make this work or is this simply not supported?

推荐答案

当您使用的收件人是很重要的 Messenger.Register 为 Messenger.Send 这并不重要。然而，在<打击>一个已知的bug 的WeakReference WeakAction 在MVVM实现，持有引用到收件人，但是，它应该释放它。

The recipient is important when you use Messenger.Register for Messenger.Send it is not important. However, there is a known bug in the WeakReference WeakAction implementation in MVVM that holds a reference to the recipient, although, it should release it.

总之，如果你是内视图模型，请确保你调用清理。在视图中，调用 Messenger.Unregister（本）在卸载事件，例如

In short, if you are inside a ViewModel, make sure that you call Cleanup. In a view, call Messenger.Unregister(this) in the Unloaded event e.g.

public MyView() {
    this.Unloaded += (o, e) => { Messenger.Unregister(this); }
}

在其他类你将不得不要么实施的IDisposable 或者使用一些其他的机制来注销该邮件收件人。

In other classes your will have to either implement IDisposable or use some other mechanism to unregister the message recipient.

另请参阅：

• <一个href="http://stackoverflow.com/questions/6319862/mvvm-light-listener-not-releasing-deterministic-finalization-for-registered-obj/6324552#6324552">MVVM光监听器不释放/确定性终结了注册的对象？
• <一个href="http://stackoverflow.com/questions/6919209/does-mvvm-light-v3-unregister-work-properly/6922299#6922299">Does MVVM光V3注销正常工作？
• <一个href="http://stackoverflow.com/questions/7036873/when-to-dispose-viewmodel-in-mvvm-light/7037282#7037282">When处置视图模型中MVVM光

• MVVM Light Listener not releasing / deterministic finalization for registered object?
• Does mvvm light v3 unregister work properly?
• When to dispose ViewModel in MVVM Light

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