我是否必须取消订阅ActivatedRoute(例如params)可观察对象? [英] Do I have to unsubscribe from ActivatedRoute (e.g. params) observables?

问题描述

我发现许多示例，其中ActivatedRoute诸如params或url的可观察对象已订阅但未取消订阅.

I find many examples where ActivatedRoute Observables like params or url are subscribed but not unsubscribed.

constructor(private route: ActivatedRoute) {}

ngOnInit() {
  this.route.params
    // (+) converts string 'id' to a number
    .switchMap((params: Params) => this.service.getHero(+params['id']))
    .subscribe((hero: Hero) => this.hero = hero);
}

• 是否为每次创建组件自动销毁了路由对象和订阅并重新创建了它们?
• 我是否需要考虑退订那些Observable?
• 如果没有，您能否解释Router.routerState中的ActivatedRoute对象树的情况?
• Are the route objects and subscriptions destroyed automagically and newly created for every component creation?
• Do I have to care about unsubscribing from those Observables?
• If not, can you explain what happens with the tree of ActivatedRoute objects in Router.routerState?

推荐答案

从文档中:

订阅组件中的可观察对象时，几乎总是在组件被破坏时取消订阅.

When subscribing to an observable in a component, you almost always arrange to unsubscribe when the component is destroyed.

有一些不需要观察的例外观察点.可观察到的ActivatedRoute除外.

There are a few exceptional observables where this is not necessary. The ActivatedRoute observables are among the exceptions.

ActivatedRoute及其可观察值与路由器本身绝缘.当不再需要路由组件并且注入的ActivatedRoute随之死亡时，Router会销毁它.

The ActivatedRoute and its observables are insulated from the Router itself. The Router destroys a routed component when it is no longer needed and the injected ActivatedRoute dies with it.

随时可以退订.这是无害的，绝不是坏习惯.

Feel free to unsubscribe anyway. It is harmless and never a bad practice.

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