angular - 如何解决路由中的 angularfire2 数据？

Question

试图从我的路由器中解析来自 angularfire2 的一些数据。当我通过它时，return of('Hello Alligator!')我的组件日志Hello Alligator但是当我尝试从 angularfire 服务中解析数据时，它只是挂起并且永远不会解析。我还想将它设置在我仍然可以添加到集合中的位置。我究竟做错了什么？

//SmsListResolverService    

import {Resolve, ActivatedRouteSnapshot, RouterStateSnapshot} from '@angular/router'
import {Observable, of} from 'rxjs'
import { SMS } from './SMS.interface';
import {FirebaseService} from '../_shared/firebase.service'
import { Injectable } from '@angular/core';

import { AngularFirestore } from '@angular/fire/firestore';

@Injectable()
export class SmsListResolverService implements Resolve<Observable<any>>{
    constructor(private db:AngularFirestore){

    }
    resolve(){
        // this_works-----> return of('Hello Alligator!') 
        return this.db.collection('messages').valueChanges() //not this

    }
}


//Route module 
export const routes: Routes = [
  {
    path: 'chat',
    component: SmsComponent,
    resolve: { messages: SmsListResolverService }
 }
];

//component

export class SmsComponent{ 
  constructor(public sms: SmsService, private route:ActivatedRoute) {

    console.log(this.route.snapshot.data)
  }

Answer 1

就像哈维尔说你需要订阅你的 valueChanges：

resolve(){
  // this_works-----> return of('Hello Alligator!') 
 this.db.collection('messages').valueChanges().subscribe((value: any) => {
   return value;
 });
}