RxSwift订阅将在启动时起作用

Question

我是第一次使用RxSwift。它将从我的服务器加载帖子列表。第一次只需要运行loadPostList，但只需初始化模型，就会调用nextPage。

请让我知道我做错了什么。

class PostNetworkModel {
    var nextPage:BehaviorSubject<Void> = BehaviorSubject(value: ())
    var reFresh:BehaviorSubject<Void> = BehaviorSubject(value: ())
    var raiseError:BehaviorSubject<Void> = BehaviorSubject(value: ())
    var isLoadingComplete = false
    private var pageNo = BehaviorRelay(value: 1)
    var postList : BehaviorRelay<[Post]> = BehaviorRelay(value: [])
    let disposeBag = DisposeBag()
    init() {
        loadPostList()
            .bind(to: postList)
            .disposed(by: disposeBag)

        postList
            .asObservable()
            .subscribe({ ( _) in
                self.isLoadingComplete = true
            })
            .disposed(by: disposeBag)

        nextPage
            .asObservable()
            .subscribe(onNext: { [weak self] ( _) in
                print("nextPage")
                if (self?.isLoadingComplete)!{
                    self?.isLoadingComplete = false
                    self?.pageNo.accept(self!.pageNo.value + 1)
                }
            })
            .disposed(by: disposeBag)
     }
}

Answer 1

BehaviorSubject接受初始值作为构造函数参数，因为其规范如下：

观察者可以订阅主题以接收最后（或初始）值以及所有后续通知。

意思是nextPage将触发下一个甚至订阅。您可能希望将此类的所有BehaviorSuject更改为PublishSubject

class PostNetworkModel {
    var nextPage:PublishSubject<Void> = PublishSubject()
    var reFresh:PublishSubject<Void> = PublishSubject()
    var raiseError:PublishSubject<Void> = PublishSubject()
    var isLoadingComplete = false
    private var pageNo = BehaviorRelay(value: 1)
    var postList : PublishRelay<[Post]> = PublishRelay()

    let disposeBag = DisposeBag()
    init() {
        loadPostList()
            .bind(to: postList)
            .disposed(by: disposeBag)

        postList
            .asObservable()
            .subscribe({ ( _) in
                self.isLoadingComplete = true
            })
            .disposed(by: disposeBag)

        nextPage
            .asObservable()
            .subscribe(onNext: { [weak self] ( _) in
                print("nextPage")
                if (self?.isLoadingComplete)!{
                    self?.isLoadingComplete = false
                    self?.pageNo.accept(self!.pageNo.value + 1)
                }
            })
            .disposed(by: disposeBag)
     }
}

请注意，我保持pageNo为BehaviorRelay，因为这个observable有一个初始值是有道理的。