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首页 > 解决方案 > 我在这里有一个组件，我用于订阅和订阅后的方法并取消订阅订阅的方法，以避免内存泄漏

angular - 我在这里有一个组件，我用于订阅和订阅后的方法并取消订阅订阅的方法，以避免内存泄漏

问题描述

服务代码

private posts: Post[] = [];
  private postsupdated = new Subject<Post[]>();
  getPost() {
    return [...this.posts]
  }
  getPostsUpdatedListener() {
    return this.postsupdated.asObservable()
  }

  addPosts(title: String, content: String) {
    const post: Post = { title: title, content: content }
    this.posts.push(post)
    this.postsupdated.next([...this.posts])
  }
  constructor() { }

组件代码

  Posts: Post[] = [];
  private postsSub = Subscription;
  ngOnInit(): void {
    this.Posts = this.postService.getPost();
    this.postsSub = this.postService.getPostsUpdatedListener()
      .subscribe((posts: Post[]) => {
        this.Posts = posts
      })
  }
  ngOnDestroy() {
    this.postsSub.unsubscribe();
  }

类型“订阅”缺少“类型订阅”类型中的以下属性：原型、空和属性“取消订阅”在类型“订阅”上不存在。如何解决？

标签： angularrxjs-observables

解决方案

您正在分配 postsSub 而不是声明类型

private postsSub: Subscription;

重写了一些代码：

//Service
private _posts$ = new BehaviourSubject<Post[]>([]);
posts$ = this.posts.asObservable();

  addPosts(title: String, content: String) {
    const post: Post = { title: title, content: content };
    this._posts$.next([...this._posts$.getValue(), post])
  }


 // component
 posts$ = this.postService.posts$;
 _destroy$ = new Subject();

  ngOnInit(): void {
  // just for example, recommend using an async pipe in the template
    this.posts$.pipe(takeUntil(this._destroy$))
      .subscribe((posts: Post[]) => {
        // do whatever
      })
  }

 ngOnDestroy() {
    this._destroy$.next();
  }

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