Angular 2 : getting RouteParams from parent component

Question

如何从父组件获取 RouteParams？

App.ts:

@Component({
  ...
})

@RouteConfig([
  {path: '/', component: HomeComponent, as: 'Home'},
  {path: '/:username/...', component: ParentComponent, as: 'Parent'}
])

export class HomeComponent {
  ...
}

然后，在 ParentComponent 中，我可以轻松获取用户名参数并设置子路由。

Parent.ts:

@Component({
  ...
})

@RouteConfig([
  { path: '/child-1', component: ChildOneComponent, as: 'ChildOne' },
  { path: '/child-2', component: ChildTwoComponent, as: 'ChildTwo' }
])

export class ParentComponent {

  public username: string;

  constructor(
    public params: RouteParams
  ) {
    this.username = params.get('username');
  }

  ...
}

但是，我怎样才能在这些子组件中获得相同的“用户名”参数呢？做与上面相同的技巧，不这样做。因为这些参数是在 ProfileComponent 或其他地方定义的？？

@Component({
  ...
})

export class ChildOneComponent {

  public username: string;

  constructor(
    public params: RouteParams
  ) {
    this.username = params.get('username');
    // returns null
  }

  ...
}

Answer 1

更新:

现在Angular2 final已经正式发布，正确的做法是:

export class ChildComponent {

    private sub: any;

    private parentRouteId: number;

    constructor(private route: ActivatedRoute) { }

    ngOnInit() {
        this.sub = this.route.parent.params.subscribe(params => {
            this.parentRouteId = +params["id"];
        });
    }

    ngOnDestroy() {
        this.sub.unsubscribe();
    }
}

---

原创:

这是我如何使用“@angular/router”:“3.0.0-alpha.6”包做到的:

export class ChildComponent {

    private sub: any;

    private parentRouteId: number;

    constructor(
        private router: Router,
        private route: ActivatedRoute) {
    }

    ngOnInit() {
        this.sub = this.router.routerState.parent(this.route).params.subscribe(params => {
            this.parentRouteId = +params["id"];
        });
    }

    ngOnDestroy() {
        this.sub.unsubscribe();
    }
}

在此示例中，路由具有以下格式:/parent/:id/child/:childid

export const routes: RouterConfig = [
    {
        path: '/parent/:id',
        component: ParentComponent,
        children: [
            { path: '/child/:childid', component: ChildComponent }]
    }
];