RxSwift把我們程序中每一個操作都看成一個事件枣接，比如一個TextField中的文本改變耳高，一個按鈕被點擊改鲫，或者一個網(wǎng)絡請求結(jié)束等宵睦，每一個事件源就可以看成一個管道缺脉，也就是sequence瞬沦，比如TextField，當我們改變里面的文本的時候名扛，這個TextField就會不斷的發(fā)出事件院究，從他的這個sequence中不斷的流出跪妥，我們只需要監(jiān)聽這個sequence鞋喇，每流出一個事件就做相應的處理。同理眉撵，Button也是一個sequence侦香，每點擊一次就流出一個事件。也就是我們把每一步都想成是一個事件就好去理解RxSwift了纽疟」藓看下圖是不是很好理解了？
Observable和Observer
理解了觀察者模式這兩個概念就很好理解了污朽，Observable就是可被觀察的散吵，也就是我們說的寶寶，他也是事件源。而Observer就是我們的觀察者矾睦，也就是當收到事件的時候去做某些處理的爸爸媽媽晦款。觀察者需要去訂閱(subscribe)被觀察者，才能收到Observable的事件通知消息顷锰。
創(chuàng)建和訂閱被觀察者
下面創(chuàng)建被觀察者其實就是創(chuàng)建一個Obserable的sequence柬赐，就是創(chuàng)建一個流亡问，然后就可以被訂閱subscribe官紫，這樣被觀察者發(fā)出時間消失，我們就能做相應的處理
DisposeBag
DisposeBag其實就相當于iOS中的ARC似得州藕，會在適當?shù)臅r候銷毀觀察者束世，相當于內(nèi)存管理者吧。
subscribe
subscribe是訂閱sequence發(fā)出的事件床玻，比如next事件毁涉，error事件等。而subscribe(onNext:)是監(jiān)聽sequence發(fā)出的next事件中的element進行處理锈死，他會忽略error和completed事件贫堰。相對應的還有subscribe(onError:) 和 subscribe(onCompleted:)
never
never就是創(chuàng)建一個sequence，但是不發(fā)出任何事件信號待牵。
let disposeBag = DisposeBag()
let neverSequence = Observable<String>.never()
let neverSequenceSubscription = neverSequence
.subscribe { _ in
print("This will never be printed")
}.addDisposableTo(disposeBag)`
結(jié)果是什么都不打印
empty
empty就是創(chuàng)建一個空的sequence,只能發(fā)出一個completed事件
let disposeBag = DisposeBag()
Observable<Int>.empty()
.subscribe { event in
print(event)
}
.addDisposableTo(disposeBag)
completed
just
just是創(chuàng)建一個sequence只能發(fā)出一種特定的事件其屏，能正常結(jié)束
let disposeBag = DisposeBag()
Observable.just("??")
.subscribe { event in
print(event)
}
.addDisposableTo(disposeBag)
next(??)
completed
of
of是創(chuàng)建一個sequence能發(fā)出很多種事件信號
let disposeBag = DisposeBag()
Observable.of("??", "??", "??", "??")
.subscribe(onNext: { element in
print(element)
})
.addDisposableTo(disposeBag)
??
??
??
如果把上面的onNext:去掉的話，結(jié)果會是這樣子缨该，也正好對應了我們subscribe中偎行，subscribe只監(jiān)聽事件。
next(??)
next(??)
next(??)
next(??)
completed
from
from就是從集合中創(chuàng)建sequence贰拿，例如數(shù)組蛤袒，字典或者Set
let disposeBag = DisposeBag()
Observable.from(["??", "??", "??", "??"])
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
create
我們也可以自定義可觀察的sequence，那就是使用create
create操作符傳入一個觀察者observer膨更，然后調(diào)用observer的onNext妙真，onCompleted和onError方法。返回一個可觀察的obserable序列
let disposeBag = DisposeBag()
let myJust = { (element: String) -> Observable<String> in
return Observable.create { observer in
observer.on(.next(element))
observer.on(.completed)
return Disposables.create()
}
}
myJust("??")
.subscribe { print($0) }
.addDisposableTo(disposeBag)
next(??)
completed
range
range就是創(chuàng)建一個sequence荚守，他會發(fā)出這個范圍中的從開始到結(jié)束的所有事件
let disposeBag = DisposeBag()
Observable.range(start: 1, count: 10)
.subscribe { print($0) }
.addDisposableTo(disposeBag)
next(1)
next(2)
next(3)
next(4)
next(5)
next(6)
next(7)
next(8)
next(9)
next(10)
completed
repeatElement
let disposeBag = DisposeBag()
Observable.repeatElement("??")
.take(3)
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
??
??
??
generate
let disposeBag = DisposeBag()
Observable.generate(
initialState: 0,
condition: { $0 < 3 },
iterate: { $0 + 1 }
)
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
0
1
2
deferred
deferred會為每一為訂閱者observer創(chuàng)建一個新的可觀察序列
let disposeBag = DisposeBag()
var count = 1
let deferredSequence = Observable<String>.deferred {
print("Creating \(count)")
count += 1
return Observable.create { observer in
print("Emitting...")
observer.onNext("??")
observer.onNext("??")
observer.onNext("??")
return Disposables.create()
}
}
deferredSequence
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
deferredSequence
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
Creating 1
Emitting...
??
??
??
Creating 2
Emitting...
??
??
??
error
創(chuàng)建一個可觀察序列隐孽，但不發(fā)出任何正常的事件，只發(fā)出error事件并結(jié)束
let disposeBag = DisposeBag()
Observable<Int>.error(TestError.test)
.subscribe { print($0) }
.addDisposableTo(disposeBag)
error(test)
doOn
doOn我感覺就是在直接onNext處理時候健蕊，先執(zhí)行某個方法菱阵，doOnNext( :)方法就是在subscribe(onNext:)前調(diào)用，doOnCompleted(:)就是在subscribe(onCompleted:)前面調(diào)用的缩功。
let disposeBag = DisposeBag()
Observable.of("??", "??", "??", "??")
.do(onNext: { print("Intercepted:", $0) }, onError: { print("Intercepted error:", $0) }, onCompleted: { print("Completed") })
.subscribe(onNext: { print($0) },onCompleted: { print("結(jié)束") })
.addDisposableTo(disposeBag)
Intercepted: ??
??
Intercepted: ??
??
Intercepted: ??
??
Intercepted: ??
??
Completed
結(jié)束
學會使用Subjects
Subjet是observable和Observer之間的橋梁晴及，一個Subject既是一個Obserable也是一個Observer，他既可以發(fā)出事件嫡锌，也可以監(jiān)聽事件虑稼。
PublishSubject
當你訂閱PublishSubject的時候琳钉，你只能接收到訂閱他之后發(fā)生的事件。subject.onNext()發(fā)出onNext事件蛛倦，對應的還有onError()和onCompleted()事件
let disposeBag = DisposeBag()
let subject = PublishSubject<String>()
subject.addObserver("1").addDisposableTo(disposeBag)
subject.onNext("??")
subject.onNext("??")
subject.addObserver("2").addDisposableTo(disposeBag)
subject.onNext("???")
subject.onNext("???")`
Subscription: 1 Event: next(??)
Subscription: 1 Event: next(??)
Subscription: 1 Event: next(???)
Subscription: 2 Event: next(???)
Subscription: 1 Event: next(???)
Subscription: 2 Event: next(???)`
ReplaySubject
當你訂閱ReplaySubject的時候歌懒，你可以接收到訂閱他之后的事件，但也可以接受訂閱他之前發(fā)出的事件溯壶，接受幾個事件取決與bufferSize的大小
let disposeBag = DisposeBag()
let subject = ReplaySubject<String>.create(bufferSize: 1)
subject.addObserver("1").addDisposableTo(disposeBag)
subject.onNext("??")
subject.onNext("??")
subject.addObserver("2").addDisposableTo(disposeBag)
subject.onNext("???")
subject.onNext("???")
Subscription: 1 Event: next(??)
Subscription: 1 Event: next(??)
Subscription: 2 Event: next(??) //訂閱之后還可以接受一次前面發(fā)出的事件
Subscription: 1 Event: next(???)
Subscription: 2 Event: next(???)
Subscription: 1 Event: next(???)
Subscription: 2 Event: next(???)
BehaviorSubject
當你訂閱了BehaviorSubject及皂，你會接受到訂閱之前的最后一個事件。
let disposeBag = DisposeBag()
let subject = BehaviorSubject(value: "??")
subject.addObserver("1").addDisposableTo(disposeBag)
subject.onNext("??")
subject.onNext("??")
subject.addObserver("2").addDisposableTo(disposeBag)
subject.onNext("???")
subject.onNext("???")
subject.addObserver("3").addDisposableTo(disposeBag)
subject.onNext("??")
subject.onNext("??")
Subscription: 1 Event: next(??)
Subscription: 1 Event: next(??)
Subscription: 1 Event: next(??)
Subscription: 2 Event: next(??) //訂閱之前的最后一個事件
Subscription: 1 Event: next(???)
Subscription: 2 Event: next(???)
Subscription: 1 Event: next(???)
Subscription: 2 Event: next(???)
Subscription: 3 Event: next(???) //訂閱之前的最后一個事件
Subscription: 1 Event: next(??)
Subscription: 3 Event: next(??)
Subscription: 2 Event: next(??)
Subscription: 1 Event: next(??)
Subscription: 3 Event: next(??)
Subscription: 2 Event: next(??)
PublishSubject, ReplaySubject和BehaviorSubject是不會自動發(fā)出completed事件的且改。
Variable
Variable是BehaviorSubject一個包裝箱验烧，就像是一個箱子一樣，使用的時候需要調(diào)用asObservable()拆箱又跛，里面的value是一個BehaviorSubject碍拆，他不會發(fā)出error事件，但是會自動發(fā)出completed事件
let disposeBag = DisposeBag()
let variable = Variable("??")
variable.asObservable().addObserver("1").addDisposableTo(disposeBag)
variable.value = "??"
variable.value = "??"
variable.asObservable().addObserver("2").addDisposableTo(disposeBag)
variable.value = "???"
variable.value = "???"
Subscription: 1 Event: next(??)
Subscription: 1 Event: next(??)
Subscription: 1 Event: next(??)
Subscription: 2 Event: next(??)
Subscription: 1 Event: next(???)
Subscription: 2 Event: next(???)
Subscription: 1 Event: next(???)
Subscription: 2 Event: next(???)
Subscription: 1 Event: completed
Subscription: 2 Event: completed
聯(lián)合操作
聯(lián)合操作就是把多個Observable流合成單個Observable流
startWith
在發(fā)出事件消息之前慨蓝，先發(fā)出某個特定的事件消息感混。比如發(fā)出事件2 ，3然后我startWith(1)礼烈，那么就會先發(fā)出1弧满，然后2 ，3.
let disposeBag = DisposeBag()
Observable.of("2", "3")
.startWith("1")
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
1
2
3
merge
合并兩個Observable流合成單個Observable流济丘，根據(jù)時間軸發(fā)出對應的事件
let disposeBag = DisposeBag()
let subject1 = PublishSubject<String>()
let subject2 = PublishSubject<String>()
Observable.of(subject1, subject2)
.merge()
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
subject1.onNext("???")
subject1.onNext("???")
subject2.onNext("①")
subject2.onNext("②")
subject1.onNext("??")
subject2.onNext("③")
???
???
①
②
??
③
zip
let disposeBag = DisposeBag()
let stringSubject = PublishSubject<String>()
let intSubject = PublishSubject<Int>()
Observable.zip(stringSubject, intSubject) { stringElement, intElement in
"\(stringElement) \(intElement)"
}
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
stringSubject.onNext("???")
stringSubject.onNext("???")
intSubject.onNext(1)
intSubject.onNext(2)
stringSubject.onNext("??")
intSubject.onNext(3)
??? 1 將stringSubject和intSubject壓縮到一起共同處理
??? 2
?? 3
combineLatest
綁定超過最多不超過8個的Observable流谱秽，結(jié)合在一起處理。和Zip不同的是combineLatest是一個流的事件對應另一個流的最新的事件摹迷，兩個事件都會是最新的事件疟赊，可將下圖與Zip的圖進行對比。
let disposeBag = DisposeBag()
let stringSubject = PublishSubject<String>()
let intSubject = PublishSubject<Int>()
Observable.combineLatest(stringSubject, intSubject) { stringElement, intElement in
"\(stringElement) \(intElement)"
}
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
stringSubject.onNext("???")
stringSubject.onNext("???")
intSubject.onNext(1)
intSubject.onNext(2)
stringSubject.onNext("??")
??? 1
??? 2
?? 2
switchLatest
switchLatest可以對事件流進行轉(zhuǎn)換峡碉，本來監(jiān)聽的subject1近哟，我可以通過更改variable里面的value更換事件源。變成監(jiān)聽subject2了
let disposeBag = DisposeBag()
let subject1 = BehaviorSubject(value: "??")
let subject2 = BehaviorSubject(value: "??")
let variable = Variable(subject1)
variable.asObservable()
.switchLatest()
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
subject1.onNext("??")
subject1.onNext("??")
variable.value = subject2
subject1.onNext("??")
subject2.onNext("??")
variable.value = subject1
subject2.onNext("田騰飛")
subject1.onNext("沸騰天"
??
??
??
??
??
??
沸騰天
變換操作
map
通過傳入一個函數(shù)閉包把原來的sequence轉(zhuǎn)變?yōu)橐粋€新的sequence的操作
et disposeBag = DisposeBag()
Observable.of(1, 2, 3)
.map { $0 * $0 }
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
1 每一個元素自己相乘
4
9
flatMap
將一個sequence轉(zhuǎn)換為一個sequences鲫寄，當你接收一個sequence的事件吉执，你還想接收其他sequence發(fā)出的事件的話可以使用flatMap，她會將每一個sequence事件進行處理以后地来，然后再以一個sequence形式發(fā)出事件戳玫。而且flatMap有一次拆包動作，請看代碼解析未斑。
let disposeBag = DisposeBag()
struct Player {
var score: Variable<Int> //里面是一個Variable
}
let ???? = Player(score: Variable(80))
let ???? = Player(score: Variable(90))
let ?? = Player(score: Variable(550))
let player = Variable(????) //將player轉(zhuǎn)為Variable
player.asObservable() //拆箱轉(zhuǎn)成可被監(jiān)聽的sequence
.flatMap { $0.score.asObservable() } // flatMap有一次拆包動作咕宿，$0本來應該是一個BehaviorSubject類型，但是直接訪問了score。所以猜想flatMap對behaviorSubject進行了onNext拆包取數(shù)據(jù)
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
????.score.value = 85
player.value = ???? //更換了value府阀，相當于又添加了一個sequence缆镣，兩個sequence都可以接收
????.score.value = 95
????.score.value = 222
player.value = ??
????.score.value = 100`
80
85
90
95
222
550
100
flatMapLatest
flatMapLatest只會接收最新的value事件，將上例改為flatMapLatest试浙。結(jié)果為
80
85
90
550
scan
scan就是給一個初始化的數(shù)董瞻，然后不斷的拿前一個結(jié)果和最新的值進行處理操作。
let disposeBag = DisposeBag()
Observable.of(10, 100, 1000)
.scan(1) { aggregateValue, newValue in
aggregateValue + newValue
}
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
11
111
1111
過濾和約束
filter
filter很好理解田巴，就是過濾掉某些不符合要求的事件
Observable.of(
"??", "??", "??",
"??", "??", "??",
"??", "??", "??")
.filter {
$0 == "??"
}
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
??
??
??
distinctUntilChanged
distinctUntilChanged就是當下一個事件與前一個事件是不同事件的事件才進行處理操作
let disposeBag = DisposeBag()
Observable.of("??", "??", "??", "??", "??", "??", "??")
.distinctUntilChanged()
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
??
??
??
??
??
elementAt
只處理在指定位置的事件
let disposeBag = DisposeBag()
Observable.of("??", "??", "??", "??", "??", "??")
.elementAt(3)
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
??
single
找出在sequence只發(fā)出一次的事件钠糊，如果超過一個就會發(fā)出error錯誤
Observable.of("??", "??", "??", "??", "??", "??")
.single()
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
?? //單一信號超過了一個
Received unhandled error: /var/folders/hz/v15ld5mj0nqf83d21j13y0tw0000gn/T/./lldb/7229/playground107.swift:69:__lldb_expr_107 -> Sequence contains more than one element.
Observable.of("??", "??", "??", "??", "??", "??")
.single { $0 == "??" } //青蛙只有一個，completed
.subscribe { print($0) }
.addDisposableTo(disposeBag)
Observable.of("??", "??", "??", "??", "??", "??")
.single { $0 == "??" } //兔子有兩個固额，會發(fā)出error
.subscribe { print($0) }
.addDisposableTo(disposeBag)
Observable.of("??", "??", "??", "??", "??", "??")
.single { $0 == "??" } //沒有藍色球眠蚂，會發(fā)出error
.subscribe { print($0) }
.addDisposableTo(disposeBag)
take
只處理前幾個事件信號,
let disposeBag = DisposeBag()
Observable.of("??", "??", "??", "??", "??", "??")
.take(3)
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
??
??
??
takeLast
只處理后幾個事件信號
let disposeBag = DisposeBag()
Observable.of("??", "??", "??", "??", "??", "??")
.takeLast(3)
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
??
??
??
takeWhile
當條件滿足的時候進行處理
let disposeBag = DisposeBag()
Observable.of(1, 2, 3, 4, 5, 6)
.takeWhile { $0 < 4 }
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
1
2
3
takeUntil
接收事件消息煞聪，直到另一個sequence發(fā)出事件消息的時候斗躏。
let disposeBag = DisposeBag()
let sourceSequence = PublishSubject<String>()
let referenceSequence = PublishSubject<String>()
sourceSequence
.takeUntil(referenceSequence)
.subscribe { print($0) }
.addDisposableTo(disposeBag)
sourceSequence.onNext("??")
sourceSequence.onNext("??")
sourceSequence.onNext("??")
referenceSequence.onNext("??") //停止接收消息
sourceSequence.onNext("??")
sourceSequence.onNext("??")
sourceSequence.onNext("??")
next(??)
next(??)
next(??)
completed
skip
取消前幾個事件
let disposeBag = DisposeBag()
Observable.of("??", "??", "??", "??", "??", "??")
.skip(2)
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
??
??
??
??
skipWhile
滿足條件的事件消息都取消
let disposeBag = DisposeBag()
Observable.of(1, 2, 3, 4, 5, 6)
.skipWhile { $0 < 4 }
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
4
5
6
skipWhileWithIndex
滿足條件的都被取消，傳入的閉包同skipWhile有點區(qū)別而已
Observable.of("??", "??", "??", "??", "??", "??")
.skipWhileWithIndex { element, index in
index < 3
}
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
skipUntil
直到某個sequence發(fā)出了事件消息昔脯，才開始接收當前sequence發(fā)出的事件消息
let disposeBag = DisposeBag()
let sourceSequence = PublishSubject<String>()
let referenceSequence = PublishSubject<String>()
sourceSequence
.skipUntil(referenceSequence)
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
sourceSequence.onNext("??")
sourceSequence.onNext("??")
sourceSequence.onNext("??")
referenceSequence.onNext("??")
sourceSequence.onNext("??")
sourceSequence.onNext("??")
sourceSequence.onNext("??")
}
數(shù)學操作
toArray
將sequence轉(zhuǎn)換成一個array啄糙，并轉(zhuǎn)換成單一事件信號，然后結(jié)束
let disposeBag = DisposeBag()
Observable.range(start: 1, count: 10)
.toArray()
.subscribe { print($0) }
.addDisposableTo(disposeBag)
next([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
completed
reduce
用一個初始值云稚，對事件數(shù)據(jù)進行累計操作隧饼。reduce接受一個初始值，和一個操作符號
let disposeBag = DisposeBag()
Observable.of(10, 100, 1000)
.reduce(1, accumulator: +)
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
1111
concat
concat會把多個sequence和并為一個sequence静陈，并且當前面一個sequence發(fā)出了completed事件燕雁，才會開始下一個sequence的事件。
在第一sequence完成之前鲸拥，第二個sequence發(fā)出的事件都會被忽略拐格，但會接收一完成之前的二發(fā)出的最后一個事件。不好解釋刑赶，看例子說明
let disposeBag = DisposeBag()
let subject1 = BehaviorSubject(value: "??")
let subject2 = BehaviorSubject(value: "??")
let variable = Variable(subject1)
variable.asObservable()
.concat()
.subscribe { print($0) }
.addDisposableTo(disposeBag)
subject1.onNext("??")
subject1.onNext("??")
variable.value = subject2
subject2.onNext("??") //1完成前捏浊，會被忽略
subject2.onNext("teng") //1完成前，會被忽略
subject2.onNext("fei") //1完成前的最后一個撞叨，會被接收
subject1.onCompleted()
subject2.onNext("??")
next(??)
next(??)
next(??)
next(fei)
next(??)
連接性操作
Connectable Observable有訂閱時不開始發(fā)射事件消息金踪，而是僅當調(diào)用它們的connect（）方法時。這樣就可以等待所有我們想要的訂閱者都已經(jīng)訂閱了以后牵敷，再開始發(fā)出事件消息胡岔，這樣能保證我們想要的所有訂閱者都能接收到事件消息。其實也就是等大家都就位以后枷餐，開始發(fā)出消息
publish
將一個正常的sequence轉(zhuǎn)換成一個connectable sequence
let intSequence = Observable<Int>.interval(1, scheduler: MainScheduler.instance)
.publish()
_ = intSequence
.subscribe(onNext: { print("Subscription 1:, Event: \($0)") })
delay(2) { _ = intSequence.connect() } //相當于把事件消息推遲了兩秒
delay(4) {
_ = intSequence
.subscribe(onNext: { print("Subscription 2:, Event: \($0)") })
}
delay(6) {
_ = intSequence
.subscribe(onNext: { print("Subscription 3:, Event: \($0)") })
}
Subscription 1:, Event: 0
Subscription 1:, Event: 1
Subscription 2:, Event: 1
Subscription 1:, Event: 2
Subscription 2:, Event: 2
Subscription 1:, Event: 3
Subscription 3:, Event: 3
Subscription 2:, Event: 3
Subscription 1:, Event: 4
Subscription 3:, Event: 4
replay
將一個正常的sequence轉(zhuǎn)換成一個connectable sequence靶瘸，然后和replaySubject相似，能接收到訂閱之前的事件消息。
let intSequence = Observable<Int>.interval(1, scheduler: MainScheduler.instance)
.replay(5) //接收到訂閱之前的5條事件消息
_ = 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)") })
}
multicast
將一個正常的sequence轉(zhuǎn)換成一個connectable sequence奕锌，并且通過特性的subject發(fā)送出去著觉，比如PublishSubject，或者replaySubject惊暴，behaviorSubject等饼丘。不同的Subject會有不同的結(jié)果。
let subject = PublishSubject<Int>()
_ = subject
.subscribe(onNext: { print("Subject: \($0)") })
let intSequence = Observable<Int>.interval(1, scheduler: MainScheduler.instance)
.multicast(subject)
_ = intSequence
.subscribe(onNext: { print("\tSubscription 1:, Event: \($0)") })
delay(2) { _ = intSequence.connect() }
delay(4) {
_ = intSequence
.subscribe(onNext: { print("\tSubscription 2:, Event: \($0)") })
}
錯誤處理
catchErrorJustReturn
遇到error事件的時候辽话，就return一個值肄鸽，然后結(jié)束
let disposeBag = DisposeBag()
let sequenceThatFails = PublishSubject<String>()
sequenceThatFails
.catchErrorJustReturn("??")
.subscribe { print($0) }
.addDisposableTo(disposeBag)
sequenceThatFails.onNext("??")
sequenceThatFails.onNext("??")
sequenceThatFails.onNext("??")
sequenceThatFails.onNext("??")
sequenceThatFails.onError(TestError.test)
next(??)
next(??)
next(??)
next(??)
next(??)
completed
catchError
捕獲error進行處理，可以返回另一個sequence進行訂閱
let disposeBag = DisposeBag()
let sequenceThatFails = PublishSubject<String>()
let recoverySequence = PublishSubject<String>()
sequenceThatFails
.catchError {
print("Error:", $0)
return recoverySequence
}
.subscribe { print($0) }
.addDisposableTo(disposeBag)
sequenceThatFails.onNext("??")
sequenceThatFails.onNext("??")
sequenceThatFails.onNext("??")
sequenceThatFails.onNext("??")
sequenceThatFails.onError(TestError.test)
recoverySequence.onNext("??")
next(??)
next(??)
next(??)
next(??)
Error: test
next(??)
retry
遇見error事件可以進行重試油啤，比如網(wǎng)絡請求失敗典徘，可以進行重新連接
let disposeBag = DisposeBag()
var count = 1
let sequenceThatErrors = Observable<String>.create { observer in
observer.onNext("??")
observer.onNext("??")
observer.onNext("??")
if count == 1 {
observer.onError(TestError.test)
print("Error encountered")
count += 1
}
observer.onNext("??")
observer.onNext("??")
observer.onNext("??")
observer.onCompleted()
return Disposables.create()
}
sequenceThatErrors
.retry(3) //不傳入數(shù)字的話，只會重試一次
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
debug
debug
打印所有的訂閱, 事件和disposals
sequenceThatErrors
.retry(3)
.debug()
.subscribe(onNext: { print($0) })
.addDisposableTo(disposeBag)
RxSwift.Resources.total
查看RxSwift所有資源的占用
print(RxSwift.Resources.total)
