RxSwift - 一个 Observable 中的多个 Observable 值

Question

我想做一个像这个例子的函数。

例子

let num1 = Driver<Int>
let num2 = Driver<Int>
let result = Driver<String>

num1 = Observable.just(...).asDriver()
num2 = Observable.just(...).asDriver()
result = ??? // When both num1 and num2 are subscribed, this becomes a higher value among them as String.

// This type of code will be used
/* 
if [=10=] >=  {
    return "num1 = \([=10=])"
} else {
    return "num2 = \()"
}
*/

如何实现？

Answer 1

你可以在这里使用 RxSwift Variable 而不是 Driver 并且要监听两个 Observables，你可以使用 Observable.combineLatest(..) 方法。下面是一个如何实现它的例子：

let num1: Variable<Int>!
let num2: Variable<Int>!

let bag = DisposeBag()

num1 = Variable(1)
num2 = Variable(2)

let result = Observable.combineLatest(num1.asObservable(), num2.asObservable()) { (n1, n2) -> String in

    if n1 >= n2 {
        return "num1 = \(n1)"
    } else {
        return "num2 = \(n2)"
    }
}

result.subscribe(onNext: { (res) in
    print("Result \(res)")
}).addDisposableTo(bag)

num1.value = 5
num1.value = 8
num2.value = 10
num2.value = 7

它输出：

Result num2 = 2
Result num1 = 5
Result num1 = 8
Result num2 = 10
Result num1 = 8

Answer 2

如果可以，请不要使用变量。您已经有几个可观察对象，所以请使用它们，但是，combineLatest 是这里的解决方案：

import RxSwift

let num1 = Observable.just(3)
let num2 = Observable.just(5)
let result = Observable.combineLatest(num1, num2).map { [=10=] >=  ? "num1 = \([=10=])" : "num2 = \()" }

_ = result.subscribe(onNext: { print([=10=]) })

上面的代码在正确配置的 playground 中打印 "num2 = 5"。

RxSwift - 一个 Observable 中的多个 Observable 值

RxSwift - multiple Observable value within one Observable

ios

swift

rx-swift