如何清空一个 Angular Observable 数组？

Question

heroes$: Observable<Hero[]>;

 // Push a search term into the observable stream.
  search(term: string): void {
    this.searchTerms.next(term);
  }
 ngOnInit(): void {
    this.heroes$ = this.searchTerms.pipe(
      // wait 300ms after each keystroke before considering the term
      debounceTime(500),

      // ignore new term if same as previous term
      distinctUntilChanged(),

      // switch to new search observable each time the term changes
      switchMap((term: string) => this.searchService.searchHeroes(term)),
    );
  }

  onClear(event){
     console.log('clear observable');
       //clear array
      // I have Tried these two things to clear observable array but it not..
      this.heroes$.map(Hero => Hero = []);
      Observable.of<Hero[]>([]);
  }

我有一个带有搜索建议的搜索框有可观察数组。在 onClear 事件期间，可观察数组应该为空。

Answer 1

你可以试试

this.heroes$ = this.searchTerms.pipe(
  // wait 300ms after each keystroke before considering the term
  debounceTime(500),

  // ignore new term if same as previous term
  distinctUntilChanged(),

  // switch to new search observable each time the term changes
  switchMap((term: string) => {
    if (term === '') return Observable.of<Hero[]>([]);
    else return this.searchService.searchHeroes(term);
  }),
);

（所以 this.heroes$ 会发出 [] 如果 this.searchTerms 发出 ''）

如何清空一个 Angular Observable 数组？

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