Question

我是RxJS和Observables的新手。我按照本教程 - ＆gt;

https://coryrylan.com/blog/angular-2-observable-data-services

我的问题是，

有：

OnePage ：操纵并显示答案

服务：保持相同的答案

SecondPage ：操纵并显示答案

在该链接中，他将数据订阅到组件数据，如下所示

ngOnInit（）{ todosService.todos $ .subscribe（updatedTodos =＆gt; this.componentTodos = updatedTodos）; todosService.loadTodos（）; }

是我的，是

onPageWillEnter(){
    this.service.answers$.subscribe(updatedAnswers => {
        this.answers = updatedAnswers;
        console.log("we subscribed from questions");
    });
    this.service.load().then((rootobject:RootObject) =>{
        this.rootobject = rootobject;
        this.questions = rootobject.Item.questions;
        this.current_question = this.service.current_question;
        this.pushNextImage(0);
        console.log(this.answers, " Questions page loaded => then");
    });
    console.log(this.answers, " Questions page loaded");
}

一切都很酷。我可以更新全局“答案”和我当地的“答案”，如下所示。

markQuestion(event){
   this.current_question = this.questions[event.q_number];
   this.current_question_number = event.q_number;
   //Mark the answer in answers
   this.answers[event.q_number-1] = event.val;
   this.service._answersObserver.next(this.answers);
}

在此之后，当我在console.log中“service.answers”时，它会被更新，但是还是。

在第二页：

onPageWillEnter(){
      this.service.answers$.subscribe(updatedAnswers => {
          this.answers = updatedAnswers;
          console.log("we subscribed from questions");
      });
      //this.service._answersObserver.next(this.service.answers);
      console.log(this.service.answers$);
      console.log(this.service.answers," Page loaded AnswerSheet" , this.answers ," => answer_list");
  }

它甚至没有进入订阅事件。没有东西在控制台里。但是我这样做了：

this.service._answersObserver.next（this.service.answers）;

为什么？

这里是plunker https://plnkr.co/edit/c3fu5hsPZXslLegdeD0p?p=info

Answer 1

如果您在this.service.answers$.subscribe类的构造函数中添加AnswerSheetPage而不是onPageWillEnter方法，是否有效？

可观察 - 多个子纤维

1 个答案: