没有Http的提供者！ -从角度2迁移到4

Question

I have included HttpModule in my import as follows

app.module.ts

import { HttpModule, Http, XHRBackend, RequestOptions } from '@angular/Http';
import { ApiService } from '../services/api.service';
@NgModule({
imports: [
        BrowserModule,
        HttpModule,
        .........
    ]
providers: [
        ApiService,
        .......
    ]
    })

ApiService is my custom Service .

app.component.ts

import { Component, OnInit,NgZone } from '@angular/core';
import { Platform, AlertController, Events } from 'ionic-angular';
import { HttpModule, Http, XHRBackend, RequestOptions } from '@angular/Http';
import { StatusBar, Splashscreen, OneSignal, Network, CodePush, SyncStatus } from 'ionic-native';
import { TabsPage } from '../pages/tabs/tabs';
import { EventsPage } from '../pages/events/events'; 
import { NewsPage } from '../pages/news/news';
import { RadioPage } from '../pages/radio/radio';
import { GalleryPage } from '../pages/gallery/gallery';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/observable/fromEvent';
    declare var navigator: any;
    declare var Connection: any;

    @Component({
        templateUrl: 'app.html'

    })
    export class MyApp {

        rootPage = TabsPage;

        constructor(public platform: Platform, public alert: AlertController,
            private events: Events,
            public radioService: RadioPage,
            private codePush: CodePush,
            private ngZone: NgZone,
            public http:Http) { }

        ngOnInit() {

            this.platform.ready().then(() => {
                // My custom code
            });
        }
    }

Answer 1

You should use import { Response, Http } from '@angular/http'; in your component and service.

and as you posted above you are missing import { HttpModule } from '@angular/http';

EDIT:

Update your package.json to match the following dependencies, remove the existing node_modules directory, and then run npm instalL. Check this link .

Answer 2

You should remove

providers: [Http]

from your component annotation.

And '@angular/Http' needs to be in lowercase, '@angular/http'

Answer 3

好像您错过了导入HttpModule一样。

import { HttpModule } from '@angular/http';