如何取消订阅 Angular 2 中的 EventEmitter? [英] How to unsubscribe from EventEmitter in Angular 2?
问题描述
export declare class EventEmitter<T> extends Subject<T> {
/**
* Creates an instance of [EventEmitter], which depending on [isAsync],
* delivers events synchronously or asynchronously.
*/
constructor(isAsync?: boolean);
emit(value: T): void;
/**
* @deprecated - use .emit(value) instead
*/
next(value: any): void;
subscribe(generatorOrNext?: any, error?: any, complete?: any): any;
}
在官方的 Angular 2 Typescript 定义中,似乎无法静音或取消订阅 EventEmitter.
In Official Angular 2 Typescript definition, seems it has no way to mute or unsubscribe from EventEmitter.
随着时间的推移,我收到了回调,因为页面使用相同的 EventEmitter
I got callback over time as pages use the same EventEmitter
推荐答案
EventEmitter extends Subject.当您订阅某个主题时,您会获得一个 Subscription
,您可以稍后使用它来取消订阅.
EventEmitter extends Subject. When you subscribe to a subject you get a Subscription
which you can later use to unsubscribe.
someOutput:EventEmitter = new EventEmitter();
...
this.subscription = someOutput.subscribe(...);
...
this.subscription.unsubscribe();
提示
不要将 EventEmitter
用于除 @Output()
之外的任何其他用途.Angular 不保证 EventEmitter
将来会继续扩展 Subject
甚至类似于 Subject
的工作.
Hint
Don't use EventEmitter
for anything else but @Output()
s. Angular doesn't guarantee that EventEmitter
will keep extending Subject
or even work similar to a Subject
in the future.
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