javascript - Angular 2 : many Async pipes vs one subscribe

Question

什么对性能和“Angular 方式”更好:在 View 中有许多异步管道或在组件中有一个订阅者在 Destroy 上有取消订阅操作？

例子:

@Component({
  template: `<div> {{ post.title }} {{ post.author.name }} {{ post.category.name }} </div>`
  ...
  })
class AppComponent {
  public post: Post;
  public postSubscription;

  ngOnInit() {
    postSubscription = someObservable.subscribe((post) => {
      this.post = post;
    })
  }

 ngOnDestroy() {
    postSubscription.unsubscribe();
 }
}

或

@Component({
  template: `<div> {{ postTitle | async }} {{ postAuthorName | async }} {{ postCategoryName | async }} </div>`
  ...
  })
class AppComponent {
  public postTitle: Observable<string>;
  public postAuthorName: Observable<string>;
  public postCategoryName: Observable<string>;

  ngOnInit() {
    this.postTitle = someObservable.pluck('title');
    this.postAuthorName = someObservable.pluck('author', 'name');
    this.postCategoryName = someObservable.pluck('category', 'name');
  }
}

Answer 1

使用| async 管道更高效，因为 Angular 会收到有关更改的通知。对于第一个示例，每个更改检测周期都会检查绑定(bind)。