Question

我已尝试过这个post的解决方案，但都没有奏效。几周前我使用的是版本4和一个非常类似的项目，这段代码正在运行，但现在我在尝试获取数据时遇到此控制台错误：

Error: No provider for AngularFireDatabase!
at injectionError (core.es5.js:1169)
at noProviderError (core.es5.js:1207)
at ReflectiveInjector_.webpackJsonp.../../../core/@angular/core.es5.js.ReflectiveInjector_._throwOrNull (core.es5.js:2649)
at ReflectiveInjector_.webpackJsonp.../../../core/@angular/core.es5.js.ReflectiveInjector_._getByKeyDefault (core.es5.js:2688)
at ReflectiveInjector_.webpackJsonp.../../../core/@angular/core.es5.js.ReflectiveInjector_._getByKey (core.es5.js:2620)
at ReflectiveInjector_.webpackJsonp.../../../core/@angular/core.es5.js.ReflectiveInjector_.get (core.es5.js:2489)
at resolveNgModuleDep (core.es5.js:9492)
at _createClass (core.es5.js:9529)
at _createProviderInstance$1 (core.es5.js:9503)
at resolveNgModuleDep (core.es5.js:9488)

这是我的service.ts

    import { Injectable } from '@angular/core';
import { AngularFireDatabase, FirebaseListObservable, FirebaseObjectObservable } from 'angularfire2/database-deprecated';
import { Observable } from 'rxjs';
import { User } from '../models/users';

@Injectable()
export class UserService {

 users: FirebaseListObservable<any[]>;
  user: FirebaseObjectObservable<any>;

  constructor(public af:AngularFireDatabase) { 

    this.users = this.af.list('/users') as FirebaseListObservable<User[]>;
  }

  getUsers(){
    console.log(this.user);
    return this.user;
  }

}

接收数据的组件：

import { Component, OnInit } from '@angular/core';
import { UserService } from '../../services/user.service';
import { User } from '../../models/users';

@Component({
  selector: 'app-body',
  templateUrl: './body.component.html',
  styleUrls: ['./body.component.scss']
})
export class BodyComponent implements OnInit {
  user:User;

  constructor(public userService:UserService) { 

  }

  ngOnInit() {
    this.userService.getUsers().subscribe(users => {
      this.user = users;

    });

  }

app.module.ts ......

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';


import { AppComponent } from './app.component';
import { NavbarComponent } from './components/navbar/navbar.component';
import { BodyComponent } from './components/body/body.component';
import { FormsModule }   from '@angular/forms';
import { PlaygroundComponent } from './components/playground/playground.component';

// AngularFire Imports

import { AngularFireDatabase } from 'angularfire2/database';
import { AngularFireAuth } from 'angularfire2/auth';
import { AngularFireModule } from 'angularfire2';
import { AngularFireDatabaseModule } from 'angularfire2/database';

import { UserService } from './services/user.service';

const appRoutes: Routes = [
  {path:'', component:BodyComponent}
];

export const firebaseConfig = {
  apiKey: "AIzaSyD3KWZMx0ZJpZxXMCqtIrP-VvXE1SgXZoA",
  authDomain: "myfirstproject-d1c75.firebaseapp.com",
  databaseURL: "https://myfirstproject-d1c75.firebaseio.com",
  storageBucket: "myfirstproject-d1c75.appspot.com",
  messagingSenderId: "1027141777108"
}




@NgModule({
  declarations: [
    AppComponent,
    NavbarComponent,
    BodyComponent,
    PlaygroundComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    RouterModule.forRoot(appRoutes),
    AngularFireModule.initializeApp(firebaseConfig),
    AngularFireDatabaseModule

  ],
  providers: [
    AngularFireAuth,
    AngularFireDatabase,
    UserService

  ],
  bootstrap: [AppComponent]
})
export class AppModule { }

如果有人能告诉我这里缺少什么，我真的很赞赏。该应用程序编译，但然后我得到一个白色屏幕和控制台中的错误而不是用户数组...谢谢！

Answer 1

只需将其从提供程序中删除并导入组件内，

即可

 providers: [
   // AngularFireAuth,
   // AngularFireDatabase,
    UserService
  ],

修改

imports: [ BrowserModule, FormsModule, RouterModule.forRoot(appRoutes), AngularFireModule.initializeApp(firebaseConfig), AngularFireDatabaseModule, AngularFireAuthModule ]

Angular 4：错误：没有AngularFireDatabase的提供者

1 个答案: