从本地Json文件3获取数据

我在爱奥尼亚启动了一个虚拟项目。我尝试从本地Json文件获取数据，但出现以下错误：

我不明白为什么HttpClient没有提供程序。 要了解更多详细信息，我实际上尝试了以下教程：

如何修复此错误并获取数据

版本

import { BrowserModule } from '@angular/platform-browser';
import { ErrorHandler, NgModule } from '@angular/core';
import { IonicApp, IonicErrorHandler, IonicModule } from 'ionic-angular';
import { SplashScreen } from '@ionic-native/splash-screen';
import { StatusBar } from '@ionic-native/status-bar';

import { MyApp } from './app.component';
import { HomePage } from '../pages/home/home';
import { FirstPage } from '../pages/first/first';
import { CardsDataProvider } from '../providers/cards-data/cards-data';

@NgModule({
  declarations: [
    MyApp,
    HomePage,
    FirstPage
  ],
  imports: [
    BrowserModule,
    IonicModule.forRoot(MyApp),
  ],
  bootstrap: [IonicApp],
  entryComponents: [
    MyApp,
    HomePage,
    FirstPage
  ],
  providers: [
    StatusBar,
    SplashScreen,
    {provide: ErrorHandler, useClass: IonicErrorHandler},
    CardsDataProvider,

  ]
})
export class AppModule {}

import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import 'rxjs/add/operator/map';

/*
  Generated class for the CardsDataProvider provider.

  See https://angular.io/guide/dependency-injection for more info on providers
  and Angular DI.
*/
@Injectable()
export class CardsDataProvider {

  constructor(public http: HttpClient) {
    console.log('Hello CardsDataProvider Provider');
  }

  getLocalData() {
  this.http.get('../assets/data/cards.json').map(res => res.json()).subscribe(data => 
  {
    console.log(data);
  });  
}
}

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { FirstPage } from '../first/first';
import { CardsDataProvider } from '../../providers/cards-data/cards-data';


@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  constructor(public navCtrl: NavController, public CardsService: CardsDataProvider) {

  }
  openFirstPage() {
    this.navCtrl.push(FirstPage);
  }

  ionViewDidLoad() {
    this.CardsService.getLocalData();
  }
} 

离子3.18.0

角度5.0.1

应用程序模块.ts

import { BrowserModule } from '@angular/platform-browser';
import { ErrorHandler, NgModule } from '@angular/core';
import { IonicApp, IonicErrorHandler, IonicModule } from 'ionic-angular';
import { SplashScreen } from '@ionic-native/splash-screen';
import { StatusBar } from '@ionic-native/status-bar';

import { MyApp } from './app.component';
import { HomePage } from '../pages/home/home';
import { FirstPage } from '../pages/first/first';
import { CardsDataProvider } from '../providers/cards-data/cards-data';

@NgModule({
  declarations: [
    MyApp,
    HomePage,
    FirstPage
  ],
  imports: [
    BrowserModule,
    IonicModule.forRoot(MyApp),
  ],
  bootstrap: [IonicApp],
  entryComponents: [
    MyApp,
    HomePage,
    FirstPage
  ],
  providers: [
    StatusBar,
    SplashScreen,
    {provide: ErrorHandler, useClass: IonicErrorHandler},
    CardsDataProvider,

  ]
})
export class AppModule {}

import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import 'rxjs/add/operator/map';

/*
  Generated class for the CardsDataProvider provider.

  See https://angular.io/guide/dependency-injection for more info on providers
  and Angular DI.
*/
@Injectable()
export class CardsDataProvider {

  constructor(public http: HttpClient) {
    console.log('Hello CardsDataProvider Provider');
  }

  getLocalData() {
  this.http.get('../assets/data/cards.json').map(res => res.json()).subscribe(data => 
  {
    console.log(data);
  });  
}
}

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { FirstPage } from '../first/first';
import { CardsDataProvider } from '../../providers/cards-data/cards-data';


@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  constructor(public navCtrl: NavController, public CardsService: CardsDataProvider) {

  }
  openFirstPage() {
    this.navCtrl.push(FirstPage);
  }

  ionViewDidLoad() {
    this.CardsService.getLocalData();
  }
} 

卡片数据.ts

import { BrowserModule } from '@angular/platform-browser';
import { ErrorHandler, NgModule } from '@angular/core';
import { IonicApp, IonicErrorHandler, IonicModule } from 'ionic-angular';
import { SplashScreen } from '@ionic-native/splash-screen';
import { StatusBar } from '@ionic-native/status-bar';

import { MyApp } from './app.component';
import { HomePage } from '../pages/home/home';
import { FirstPage } from '../pages/first/first';
import { CardsDataProvider } from '../providers/cards-data/cards-data';

@NgModule({
  declarations: [
    MyApp,
    HomePage,
    FirstPage
  ],
  imports: [
    BrowserModule,
    IonicModule.forRoot(MyApp),
  ],
  bootstrap: [IonicApp],
  entryComponents: [
    MyApp,
    HomePage,
    FirstPage
  ],
  providers: [
    StatusBar,
    SplashScreen,
    {provide: ErrorHandler, useClass: IonicErrorHandler},
    CardsDataProvider,

  ]
})
export class AppModule {}

import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import 'rxjs/add/operator/map';

/*
  Generated class for the CardsDataProvider provider.

  See https://angular.io/guide/dependency-injection for more info on providers
  and Angular DI.
*/
@Injectable()
export class CardsDataProvider {

  constructor(public http: HttpClient) {
    console.log('Hello CardsDataProvider Provider');
  }

  getLocalData() {
  this.http.get('../assets/data/cards.json').map(res => res.json()).subscribe(data => 
  {
    console.log(data);
  });  
}
}

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { FirstPage } from '../first/first';
import { CardsDataProvider } from '../../providers/cards-data/cards-data';


@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  constructor(public navCtrl: NavController, public CardsService: CardsDataProvider) {

  }
  openFirstPage() {
    this.navCtrl.push(FirstPage);
  }

  ionViewDidLoad() {
    this.CardsService.getLocalData();
  }
} 

home.ts

import { BrowserModule } from '@angular/platform-browser';
import { ErrorHandler, NgModule } from '@angular/core';
import { IonicApp, IonicErrorHandler, IonicModule } from 'ionic-angular';
import { SplashScreen } from '@ionic-native/splash-screen';
import { StatusBar } from '@ionic-native/status-bar';

import { MyApp } from './app.component';
import { HomePage } from '../pages/home/home';
import { FirstPage } from '../pages/first/first';
import { CardsDataProvider } from '../providers/cards-data/cards-data';

@NgModule({
  declarations: [
    MyApp,
    HomePage,
    FirstPage
  ],
  imports: [
    BrowserModule,
    IonicModule.forRoot(MyApp),
  ],
  bootstrap: [IonicApp],
  entryComponents: [
    MyApp,
    HomePage,
    FirstPage
  ],
  providers: [
    StatusBar,
    SplashScreen,
    {provide: ErrorHandler, useClass: IonicErrorHandler},
    CardsDataProvider,

  ]
})
export class AppModule {}

import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import 'rxjs/add/operator/map';

/*
  Generated class for the CardsDataProvider provider.

  See https://angular.io/guide/dependency-injection for more info on providers
  and Angular DI.
*/
@Injectable()
export class CardsDataProvider {

  constructor(public http: HttpClient) {
    console.log('Hello CardsDataProvider Provider');
  }

  getLocalData() {
  this.http.get('../assets/data/cards.json').map(res => res.json()).subscribe(data => 
  {
    console.log(data);
  });  
}
}

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { FirstPage } from '../first/first';
import { CardsDataProvider } from '../../providers/cards-data/cards-data';


@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage {

  constructor(public navCtrl: NavController, public CardsService: CardsDataProvider) {

  }
  openFirstPage() {
    this.navCtrl.push(FirstPage);
  }

  ionViewDidLoad() {
    this.CardsService.getLocalData();
  }
} 

---

任何帮助都将不胜感激。

您在使用带Angular5的Ionic3时，正在学习Ionic2教程

要使Http从爱奥尼亚3.0开始工作，您需要在app.module.ts的导入中包含

HttpClientModule

import {HttpClientModule} from '@angular/common/http';//import

@NgModule({
  declarations: [
    MyApp,
    HomePage,
    FirstPage
  ],
  imports: [
    BrowserModule,
    IonicModule.forRoot(MyApp),
    HttpClientModule//include here
  ],
  bootstrap: [IonicApp],
  entryComponents: [
    MyApp,
    HomePage,
    FirstPage
  ],
  providers: [
    StatusBar,
    SplashScreen,
    {provide: ErrorHandler, useClass: IonicErrorHandler},
    CardsDataProvider,

  ]
})
export class AppModule {}

另外，在您的卡数据.ts中

import {Http} from '@angular/common/http';

@Injectable()
export class CardsDataProvider {

  constructor(public http: HttpClient) { //change here
    console.log('Hello CardsDataProvider Provider');
  }

有关从离子2到离子3的进一步更改，请检查。如需更改，请转至角度5检查

---

一个更简单的方法是查找最近的教程。

谢谢您的回答。我没有解决这个问题。我试图找到一本关于爱奥尼亚3的教程，但目前没有成功。如果您对如何在本地存储数据有任何建议，我将不胜感激。@Ryley38更新答案。。