RxSwift:使用rx_refreshing进行uirefreshcontrol

Question

我正在使用UIRefreshControl+ Variable绑定来重新加载数据.

然而,它正在起作用,以下对我来说是错误的:

1)我知道扩展中有一个rx_refreshing变量RXCocoa,但我无法让它在这种情况下工作.

2)我Variable两次绑定答案(这是一个数组).一旦我加载视图控制器,并在UIRefreshControl刷新时再次.

3)我检查是否UIRefreshControl清爽的部分看起来很尴尬.感觉它是否违背了使用反应的目的？

...

let answers: Variable<[Answer]> = Variable([])

override func viewDidLoad() {       
  loadAnswers()
     .shareReplay(1)
     .bindTo(answers)
     .addDisposableTo(self.disposeBag)
  setupRx()
}

func loadAnswers() -> Observable<[Answer]> {
  return Network.rxArrayRequest(Spark.Answers)
}  

func setupRx() {
  rc.rx_controlEvent(.ValueChanged)
    .map { _ in !self.rc.refreshing }
    .filter { $0 == false }
    .flatMapLatest { [unowned self] _ in
      return self.loadAnswers()
    }
    .bindTo(answers)
    .addDisposableTo(self.disposeBag)

  rc.rx_controlEvent(.ValueChanged)
    .map { _ in self.rc.refreshing }
    .filter { $0 == true }
    .subscribeNext { [unowned self] _ in
      self.rc.endRefreshing()
    }
    .addDisposableTo(self.disposeBag)
}

...

Answer 1

首先,它实际上并没有起作用.它似乎正在起作用.在您的代码中,您实际上并没有在调用之前等待网络请求完成rc.endRefreshing().相反,您只是进行网络呼叫,然后立即呼叫endRefreshing().

// `rc.rx_controlEvent(.ValueChanged)` only gets called once,
// when the user pulls down.

rc.rx_controlEvent(.ValueChanged)       // user pulled down to refresh
  .map { _ in !self.rc.refreshing }     // !true -> false 
  .filter { $0 == false }               // false == false
  .flatMapLatest { [unowned self] _ in
    return self.loadAnswers()           // request answers
  }
  .bindTo(answers)
  .addDisposableTo(self.disposeBag)

rc.rx_controlEvent(.ValueChanged)       // user pulled down to refresh
  .map { _ in self.rc.refreshing }      // true -> true
  .filter { $0 == true }                // true == true
  .subscribeNext { [unowned self] _ in
    self.rc.endRefreshing()             // end refreshing
  }
  .addDisposableTo(self.disposeBag)

为了解决问题1,你是对的,你可以rx_refreshing用来关闭刷新而不是endRefreshing().

为了解决这个问题2,我认为这Variable不是必要的或有用的,至少在这个例子中是这样.你仍然可以使用它.而且,没有必要loadAnswers()在两个地方.

为了解决问题3,是的,你可以简化这一点并使用Rx更多.

这里的代码实际上可以工作,使用rx_refreshing和简化很多事情:

let initial = Observable<Void>.just(())
let refresh = rc.rx_controlEvent(.ValueChanged).map { _ in () }
let answers = Observable.of(initial, refresh)
    .merge()
    .flatMapLatest{ _ in self.loadAnswers() }
    .shareReplayLatestWhileConnected()

answers
    .map { _ in false }
    .bindTo(rc.rx_refreshing)
    .addDisposableTo(disposeBag)

// also use `answers` to bind to your data source, etc.