angular - 无法解析 ApplicationModule : (? 的参数)

Question

Angular 的新手。我的应用程序包含 1 个服务和 3 个组件。编译成功。我收到此错误并且不知道出了什么问题:

Uncaught Error: Can't resolve all parameters for ApplicationModule: (?).

调试给了我很少的想法。似乎这个问题与具有空依赖项的 NSLocaleLocalizations 有关(如果这有意义的话) - 请参见下面的屏幕截图:

这是一些代码:如果还需要什么，请告诉我。非常感谢您的帮助 - 非常感谢。

package.json

{
  "name": "angular_app",
  "version": "0.0.0",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "build-aot": "ng build --prod --aot",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
  "@angular/animations": "^6.0.0",
  "@angular/cdk": "^6.0.0",
  "@angular/common": "^6.0.0",
  "@angular/compiler": "^6.0.0",
  "@angular/core": "^6.0.0",
  "@angular/forms": "^6.0.0",
  "@angular/http": "^6.0.0",
  "@angular/material": "^6.0.0",
  "@angular/platform-browser": "^6.0.0",
  "@angular/platform-browser-dynamic": "^6.0.0",
  "@angular/router": "^6.0.0",
  "core-js": "^2.5.4",
  "express": "^4.16.4",
  "rxjs": "^6.0.0",
  "zone.js": "^0.8.26"
  },
  "devDependencies": {
  "@angular/compiler-cli": "^6.0.0",
  "@angular-devkit/build-angular": "~0.6.0",
  "typescript": "~2.7.2",
  "@angular/cli": "~6.0.0",
  "@angular/language-service": "^6.0.0",
  "@types/jasmine": "~2.8.6",
  "@types/jasminewd2": "~2.0.3",
  "@types/node": "~8.9.4",
  "codelyzer": "~4.2.1",
  "jasmine-core": "~2.99.1",
  "jasmine-spec-reporter": "~4.2.1",
  "karma": "~1.7.1",
  "karma-chrome-launcher": "~2.2.0",
  "karma-coverage-istanbul-reporter": "~1.4.2",
  "karma-jasmine": "~1.1.1",
  "karma-jasmine-html-reporter": "^0.2.2",
  "protractor": "~5.3.0",
  "ts-node": "~5.0.1",
  "tslint": "~5.9.1"
  }

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { HttpModule } from '@angular/http';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';

import { StoriesComponent } from './pages/stories/stories.component';
import { StoryComponent } from './pages/story/story.component';
import { StageComponent } from './pages/stage/stage.component';

@NgModule({
declarations: [
  AppComponent,
  StoryComponent,
  StoriesComponent,
  StageComponent
],
imports: [
  BrowserModule,
  AppRoutingModule,
  HttpModule
],
providers: [],
bootstrap: [AppComponent]
})
export class AppModule { }

app-routing.module.ts

import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';

import { StoriesComponent } from './pages/stories/stories.component';
import { StoryComponent } from './pages/story/story.component';
import { StageComponent } from './pages/stage/stage.component';

const routes: Routes = [
  {path: '', redirectTo: '/stories', pathMatch: 'full'},
  {path: 'stories', component:StoriesComponent},
  {path: 'stories/:id', component: StoryComponent},
  {path: 'stories/:id/:id', component: StageComponent}
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule { }

stories.service.ts

import { Injectable } from '@angular/core';
import { Http } from '@angular/http';
import { map, tap } from 'rxjs/operators';

import { BehaviorSubject } from 'rxjs';

@Injectable({
  providedIn: 'root'
})

export class StoriesService {


  private _stories = new BehaviorSubject<any>(null);
  public stories = this._stories.asObservable();


  storyIdCounter = 0;
  stageIdCounter = 0;
  stateIdCounter = 0;

  constructor(private http: Http) { 
    this.getStoriesForReal().subscribe(
      (stories) => {
        console.log(stories);
        this._stories.next(stories);
      });
  }

  getStoriesForReal() {
    return this.http.get("http://localhost:3001/test").pipe(
      tap(res => console.log(res)),
      map((response) => response.json())
    );
  }

stories.component.ts

import { Component, OnInit } from '@angular/core';
import { Story } from '../../interfaces/story';
import { StoriesService } from '../../services/stories.service';


@Component({
  selector: 'app-stories',
  templateUrl: './stories.component.html',
  styleUrls: ['./stories.component.scss']
})
export class StoriesComponent implements OnInit {

  id = 0;
  storiesList: Story[];

  constructor(
    private storiesService: StoriesService) { 
    }

  ngOnInit() {
    this.storiesList = [];
    this.storiesService.stories.subscribe((stories) => {
      for (let story in stories) {
        this.storiesList.push(stories[story]);
      }
    });
  }  
}

story.component.ts

import { Component, OnInit } from '@angular/core';
import { StoriesService } from '../../services/stories.service';


@Component({
  selector: 'app-story',
  templateUrl: './story.component.html',
  styleUrls: ['./story.component.scss']
})
export class StoryComponent implements OnInit {

  constructor(
    private storiesService: StoriesService
  ) { 

  }

  ngOnInit() {

  }
}

stage.component.ts

import { Component, OnInit } from '@angular/core';

import { StoriesService } from '../../services/stories.service';

@Component({
  selector: 'app-stage',
  templateUrl: './stage.component.html',
  styleUrls: ['./stage.component.scss'],
})
export class StageComponent implements OnInit {

  constructor(
    private storiesService: StoriesService
  ) { }


  ngOnInit() {

  }
}

Answer 1

您需要在AppModule 中提供StoriesService。

  ....
  providers: [StoriesService],
  bootstrap: [AppComponent]
  .... 

此外，使用 HttpClientModule 而不是 HttpClient。