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));

}