Angular 9：forkJoin 订阅不工作

Question

我正在尝试使用 observables (rxjs 6.5.1) 在 Angular 9 的顶级组件上加载页面数据。当我单独订阅这些服务中的每一项时，我可以看到返回的数据很好：

ngOnInit(): void {

  const technicianSubscription = this.techniciansClientService.getByTechnicianId(this.technicianId).subscribe(technician => console.log(technician));

  const technicianReviewsSubscription = this.technicianReviewsClientService.getByTechnicianId(this.technicianId).subscribe(technicianReviews => console.log(technicianReviews));

}

当我尝试使用 forkJoin 时，从未返回订阅方法中的数据：

ngOnInit(): void {

  this.pageDataSubscription = forkJoin({

    technician: this.techniciansClientService.getByTechnicianId(this.technicianId),

    technicianReviews: this.technicianReviewsClientService.getByTechnicianId(this.technicianId),

  }).subscribe(

    // data is never logged here

    data => console.log(data)

  );

}

我试过传递 forkJoin 一系列服务调用，我也试过使用 zip，但无济于事。这里发生了什么事？

Answer 1

我建议使用combineLatestfrom rxjs。它更易于使用import {combineLatest} from `rxjs`;componentIsActive = true;ngOnInit(): void {  combineLatest([    this.techniciansClientService.getByTechnicianId(this.technicianId),    this.technicianReviewsClientService.getByTechnicianId(this.technicianId),  ]).pipe(    map(([technician, technicianReviews]) => ({technician, technicianReviews})),    takeWhile(() => this.componentIsActive)  ).subscribe(data => console.log(data));}