Question

我是Ionic的新手，当我将HttpClient注入我的服务类时遇到以下错误：

错误：未捕获（承诺）：错误：StaticInjectorError（AppModule）[CategoriesServiceProvider-> HttpClient]： StaticInjectorError（平台：核心）[CategoriesServiceProvider-> HttpClient]： NullInjectorError：HttpClient没有提供程序！错误：StaticInjectorError（AppModule）[CategoriesServiceProvider-> HttpClient]： StaticInjectorError（平台：核心）[CategoriesServiceProvider-> HttpClient]： NullInjectorError：HttpClient没有提供程序！

该错误是由以下Service类触发的：

import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';

@Injectable()
export class CategoriesServiceProvider {
  apiURL = 'https://randomuser.me/api/?results=10';

  constructor(private http: HttpClient) {
    console.log('Hello CategoriesServiceProvider Provider');
  }

}

如果我从构造函数中删除HttpClient，错误就会消失。

而且，以下是我的 app.module.ts 代码：

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 { TabsPage } from '../pages/tabs/tabs';
import { CategoriesPage } from '../pages/categories/categories';
import { SubscriptionsPage } from '../pages/subscriptions/subscriptions';
import { CategoriesServiceProvider } from '../providers/categories-service/categories-service';

@NgModule({
  declarations: [
    MyApp,
    TabsPage,
    CategoriesPage,
    SubscriptionsPage
  ],
  imports: [
    BrowserModule,
    IonicModule.forRoot(MyApp)
  ],
  bootstrap: [IonicApp],
  entryComponents: [
    MyApp,
    TabsPage,
    CategoriesPage,
    SubscriptionsPage
  ],
  providers: [
    StatusBar,
    SplashScreen,
    {provide: ErrorHandler, useClass: IonicErrorHandler},
    CategoriesServiceProvider
  ]
})
export class AppModule {}

任何见解都会受到赞赏。

Answer 1

在您的应用模块中添加import { HttpClientModule } from '@angular/common/http';。

在导入中，像这样添加HttpClientModule：

imports: [
  BrowserModule,
  HttpClientModule,
  IonicModule.forRoot(MyApp)
]

离子HttpClient注入错误

1 个答案: