RxSwift (7) 手动启动序列[连接性序列]

publish

转化连接序列，订阅时不会发出信号，执行connect方法时，才开始发射信号

func rx_Publish() {    let intSequence = Observable<Int>.interval(1, scheduler: MainScheduler.instance)        .publish()    _ = intSequence        .subscribe(onNext: { print("Subscription 1:, Event: \($0)") })    delay(2) { _ = intSequence.connect() }    delay(4) {        _ = intSequence            .subscribe(onNext: { print("Subscription 2:, Event: \($0)") })    }    delay(6) {        _ = intSequence            .subscribe(onNext: { print("Subscription 3:, Event: \($0)") })    }}

动态结果，复制去执行以下才能看到

replay

replay()相对于publish增加了bufferSize指定对元素的缓存大小，这样新加入的订阅者可以获取相应个数的已发送的元素

func rx_replay() {let stopObservable = PublishSubject<Int>()    let intSequence = Observable<Int>.interval(1, scheduler: MainScheduler.instance).takeUntil(stopObservable)        .replay(5)    _ = intSequence        .subscribe(onNext: { print("Subscription 1:, Event: \($0)") })    delay(2) { _ = intSequence.connect() }    delay(4) {        _ = intSequence            .subscribe(onNext: { print("Subscription 2:, Event: \($0)") })    }    delay(8) {        _ = intSequence            .subscribe(onNext: { print("Subscription 3:, Event: \($0)") })    }}

打印结果Subscription 1:, Event: 0Subscription 2:, Event: 0Subscription 1:, Event: 1Subscription 2:, Event: 1Subscription 1:, Event: 2Subscription 2:, Event: 2Subscription 1:, Event: 3Subscription 2:, Event: 3Subscription 1:, Event: 4Subscription 2:, Event: 4Subscription 3:, Event: 0//这里开始回放Subscription 3:, Event: 1Subscription 3:, Event: 2Subscription 3:, Event: 3Subscription 3:, Event: 4//回放结束Subscription 1:, Event: 5Subscription 2:, Event: 5Subscription 3:, Event: 5

multicast

multicast()需要传入一个subject，通过subject来管理向订阅者发送消

let subject = PublishSubject<Int>()_ = subject    .subscribeNext { print("Subject: \($0)") }let intSequence = Observable<Int>.interval(1, scheduler: MainScheduler.instance)    .multicast(subject)_ = intSequence    .subscribeNext { print("\tSubscription 1:, Event: \($0)") }delay(2) { intSequence.connect() }delay(4) {     _ = intSequence        .subscribeNext { print("\tSubscription 2:, Event: \($0)") }}delay(6) {     _ = intSequence        .subscribeNext { print("\tSubscription 3:, Event: \($0)") }}

打印结果Subject: 0Subscription 1:, Event: 0Subject: 1Subscription 1:, Event: 1Subscription 2:, Event: 1Subject: 2Subscription 1:, Event: 2Subscription 2:, Event: 2Subject: 3Subscription 1:, Event: 3Subscription 2:, Event: 3Subscription 3:, Event: 3Subject: 4Subscription 1:, Event: 4Subscription 2:, Event: 4Subscription 3:, Event: 4Subject: 5Subscription 1:, Event: 5Subscription 2:, Event: 5Subscription 3:, Event: 5