Bagaimana untuk Melaksanakan Skrin Memuatkan Semasa Peralihan Laluan dalam Sudut?

import {
  Router,
  Event as RouterEvent,
  NavigationStart,
  NavigationEnd,
  NavigationCancel,
  NavigationError
} from '@angular/router'

@Component({})
export class AppComponent {
  loading = true; // Initializing to true to show loading spinner on first load
  constructor(private router: Router) {
    this.router.events.subscribe((e : RouterEvent) => {
       this.navigationInterceptor(e);
     })
  }
}

  // Shows and hides the loading spinner during RouterEvent changes
  navigationInterceptor(event: RouterEvent): void {
    if (event instanceof NavigationStart) {
      this.loading = true;
    }
    if (event instanceof NavigationEnd) {
      this.loading = false;
    }
    if (event instanceof NavigationCancel) {
      this.loading = false;
    }
    if (event instanceof NavigationError) {
      this.loading = false;
    }
  }

<div>

private _navigationInterceptor(event: RouterEvent): void {
    if (event instanceof NavigationStart) {
      this.ngZone.runOutsideAngular(() => {
        this.renderer.setElementStyle(
          this.spinnerElement.nativeElement,
          'opacity',
          '1'
        )
      })
    }
    if (event instanceof NavigationEnd) {
      this._hideSpinner()
    }
    // Set loading state to false in both of the below events to
    // hide the spinner in case a request fails
    if (event instanceof NavigationCancel) {
      this._hideSpinner()
    }
    if (event instanceof NavigationError) {
      this._hideSpinner()
    }
  }

  private _hideSpinner(): void {
    this.ngZone.runOutsideAngular(() => {
      this.renderer.setElementStyle(
        this.spinnerElement.nativeElement,
        'opacity',
        '0'
      )
    })
  }