UIButton上的RxSwift和isSelected属性 [英] RxSwift and isSelected property on UIButton
本文介绍了UIButton上的RxSwift和isSelected属性的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我有三个按钮,希望一次只能选择一个按钮:
I have three buttons and I want them to be selected only one at a time:
和:
等...
我的方法是这样的:
class MyController: UIViewController {
@IBOutlet var buttonOne: UIButton!
@IBOutlet var buttonTwo: UIButton!
@IBOutlet var buttonThree: UIButton!
var buttonOneIsSelected = Variable(true)
var buttonTwoIsSelected = Variable(false)
var buttonThreeIsSelected = Variable(false)
override func viewDidLoad() {
super.viewDidLoad()
buttonOne.isSelected = true
buttonOneIsSelected.asDriver()
.drive(buttonOne.rx.isSelected)
.disposed(by: disposeBag)
buttonTwoIsSelected.asDriver()
.drive(buttonTwo.rx.isSelected)
.disposed(by: disposeBag)
buttonThreeIsSelected.asDriver()
.drive(buttonThree.rx.isSelected)
.disposed(by: disposeBag)
buttonOne.rx.tap.asObservable().map { (_) -> Bool in
return !self.buttonOne.isSelected
}
.do(onNext: { (isSelected) in
self.buttonTwoIsSelected.value = !isSelected
self.buttonThreeIsSelected.value = !isSelected
})
.bindTo(buttonOne.rx.isSelected)
.disposed(by: disposeBag)
buttonTwo.rx.tap.asObservable().map { (_) -> Bool in
return !self.buttonTwo.isSelected
}
.do(onNext: { (isSelected) in
self.buttonOneIsSelected.value = !isSelected
self.buttonThreeIsSelected.value = !isSelected
})
.bindTo(buttonTwo.rx.isSelected)
.disposed(by: disposeBag)
buttonThree.rx.tap.asObservable().map { (_) -> Bool in
return !self.buttonThree.isSelected
}
.do(onNext: { (isSelected) in
self.buttonOneIsSelected.value = !isSelected
self.buttonTwoIsSelected.value = !isSelected
})
.bindTo(buttonThree.rx.isSelected)
.disposed(by: disposeBag)
}
有没有更好的方法?它可以工作,但是有没有更好的反应性"方式通过使用RxSwift来做到这一点?
Is there a better approach? It works, but is there a better 'reactive' way to do it by using RxSwift?
推荐答案
Subject
和扩展名Variable
在大多数情况下仅在从命令式世界过渡到反应性世界时才有用.在这里,您可以不用它们.
Subject
and by extension Variable
are most of the time only useful when bridging from imperative to reactive world. Here, you could do without them.
.do(onNext:)
也是一种执行副作用的方法,这通常是您在反应式代码中所不希望的.
.do(onNext:)
is also a way to perform side effect, something you usually don't want in your reactive code.
// force unwrap to avoid having to deal with optionals later on
let buttons = [button1, button2, button3].map { $0! }
// create an observable that will emit the last tapped button (which is
// the one we want selected)
let selectedButton = Observable.from(
buttons.map { button in button.rx.tap.map { button } }
).merge()
// for each button, create a subscription that will set its `isSelected`
// state on or off if it is the one emmited by selectedButton
buttons.reduce(Disposables.create()) { disposable, button in
let subscription = selectedButton.map { $0 == button }
.bindTo(button.rx.isSelected)
// combine two disposable together so that we can simply call
// .dispose() and the result of reduce if we want to stop all
// subscriptions
return Disposables.create(disposable, subscription)
}
.addDisposableTo(disposeBag)
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