可观察与asObservable()? [英] Observable vs asObservable()?

问题描述

我是Angular2的新手，我只是好奇地知道，如果我在_showNavBar或showNavBarEmitter上进行订阅，两者的工作原理相同(请参见下面使用的代码).有什么区别吗?

I'm new to Angular2 and I'm just curious to know That If I do a subscribe on _showNavBar or on showNavBarEmitter both works same(see below code i'm using). is there any difference?

public _showNavBar: BehaviorSubject<boolean> = new BehaviorSubject<boolean>(null);
public showNavBarEmitter: Observable<boolean> = this._showNavBar.asObservable();

推荐答案

asObservable使订阅者无法访问原始主题.这样，您可以限制谁只能订阅，谁也可以发出值.

asObservable makes the original subject inaccessible for subscribers. This way you can limit who can only subscribe and who can also emit values.

要使此方法生效，您需要制作_showNavBar private.

For this to take effect you would need to make _showNavBar private though.

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