PublishSubject 不发出项目

Question

为什么下面的代码没有发出任何结果？这个 Subject 出了什么问题？我希望在我订阅的那一刻会得到一个结果，即我声明的长度。

val subject = PublishSubject.create<String>()//PublishRelay.accept() does not work as well
subject.onNext("Alpha"
subject.onNext("Beta")
subject.onNext("Gamma")
subject.onComplete()
subject.map{ it.length }
        .subscribe { println(it) }

Answer 1

Publish Subject 仅在订阅后发布项目。如果您希望所有订阅都获得所有发射，请尝试更改为 ReplaySubject，如果您想要订阅时最后一次发射，请尝试更改为 BehaviourSubject。

您可以在此处详细了解不同类型的主题：

http://reactivex.io/documentation/subject.html

val subject = ReplaySubject.create<String>()/
subject.onNext("Alpha"
subject.onNext("Beta")
subject.onNext("Gamma")
subject.onComplete()
subject.map{ it.length }
    .subscribe { println(it) }

或者，订阅，然后调用 onNext:

val subject = PublishSubject.create<String>()
subject.map{ it.length }
    .subscribe { println(it) }
subject.onNext("Alpha"
subject.onNext("Beta")
subject.onNext("Gamma")
subject.onComplete()

PublishSubject 不发出项目

PublishSubject does not emit items

android

rx-java

rx-java2

relay

publishsubject