Angular:为多个tokens提供相同的实例

@Injectable({ providedIn: 'root' })
export class AuthService {
  private isLoggedIn = false;

  login() {
    this.isLoggedIn = true;
  }

  logout() {
    this.isLoggedIn = false;
  }

  isLoggedIn$ = new BehaviorSubject<boolean>(this.isLoggedIn);
}

@Component({
  selector: 'app-user-profile',
  template: `<div *ngIf="authService.isLoggedIn$ | async">Logged in</div>`
})
export class UserProfileComponent {
  constructor(public authService: AuthService) {}
}

// auth.service.ts
@Injectable({ providedIn: 'root' })
export class AuthService {
  private isLoggedIn = false;

  login() {
    this.isLoggedIn = true;
  }

  logout() {
    this.isLoggedIn = false;
  }

  isLoggedIn$ = new BehaviorSubject<boolean>(this.isLoggedIn);
}

// user-profile.component.ts
@Component({
  selector: 'app-user-profile',
  template: `<div *ngIf="authService.isLoggedIn$ | async">Logged in</div>`
})
export class UserProfileComponent {
  constructor(public authService: AuthService) {}
}