Rxswift Observable.of 和 Observable<String>.create 有什么区别 [英] Rxswift What difference between Observable.of and Observable&lt;String&gt;.create

问题描述

我是 rxSwift 的新手.我在创建 Observable 时发现了一些不同之处Observable.of 和 Observable.create

I'm a newbie in rxSwift. I found some difference when create Observable by Observable.of and Observable<String>.create

    Observable<String>.create { observer in

    observer.onNext("1")

    observer.onNext("2")

    return Disposables.create()
    }.take(3).toArray().subscribe(onNext: { (item) in
        print(item)
    }).disposed(by: disposeBag)

未发出 util 至少收到 3 个事件.以这种方式观察者从未发出过.但是:

Not emitted util received at least 3 event. In this way observer never emitted. But with:

    Observable.of("1", "2")
    // 2
    .take(3).toArray()
    .subscribe(onNext: {
        print($0) })
    .disposed(by: disposeBag)

但是当我通过这种方式创建时.即使我只有 2 个元素，Observer 也总是发出.不知道有什么区别

But when i create by this way. Observer always emitted even if i just have 2 elements. I don't known what difference.

推荐答案

主要区别在于 of 也发送一个完成的事件.你可以检查下面的例子，第二个完成"不会被调用.

The main difference is that of sends a completed event as well. You can check the example below, the second "completed" will not be called.

你必须在 observer.onNext("2") 之后写 observer.onCompleted() 以便有相同的逻辑.

You have to write observer.onCompleted() after observer.onNext("2") it order to have the same logic.

Observable.of("1", "2").subscribe(onCompleted: {
    print("completed")
})

Observable<String>.create { observer in
        observer.onNext("1")
        observer.onNext("2")
        return Disposables.create()
    }
    .subscribe(onCompleted: {
        print("completed")
    })

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