Angular 2:没有ConnectionBackend的提供者！怎么解决? [英] Angular 2: No provider for ConnectionBackend! How to solve?

问题描述

我在这里遵循本教程

I was following this tutorial here https://tableless.com.br/criando-uma-aplicacao-movel-com-ionic-2-e-angular-2-em-dez-passos/ but things dind't go as expectend and I got stuck in a "No provider for..." error. (The tutorial is in Portuguese, but I think you'll get it only by looking at the code examples.)

代码如下:

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { Http } from '@angular/http';
import 'rxjs/add/operator/map';

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {
  public feeds: Array<string>;
  private url: string = "https://www.reddit.com/new.json";  
  constructor(public navCtrl: NavController, public http: Http) {
    this.http.get(this.url).map(res => res.json())
      .subscribe(data => {
        this.feeds = data.data.children;
      }); 
  }
}

首先，错误是由于"Http"引起的. 然后我(认为我)解决了这个问题:

First, the error was for "Http". Then I (think I) solved with this:

@Component({
  selector: 'page-home',
  providers: [Http],
  templateUrl: 'home.html'
})

但是现在错误是没有为ConnectionBackend提供程序！"，我不知道如何解决.

But now the error is a "No provider for ConnectionBackend!", and I don't know how to solve.

推荐答案

您需要将HttpModule添加到app.module中的导入中.

You need to add the HttpModule to the imports in the app.module.

@NgModule({
  imports: [
    HttpModule, <----
    BrowserModule,
    HttpModule,
  ],
  declarations: [AppComponent],
  providers: [],
  bootstrap: [AppComponent],
})
export class AppModule {
}

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