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angular - Angular Ionic：“对象”类型上不存在属性“json”

问题描述

我正在创建一个显示 github 用户及其详细信息的 Ionic 2 项目。我创建了名为 github-users.ts 的服务文件，编译器在 .json() 方法中显示了这个错误。

“对象”类型上不存在属性“json”

这是我的github-users.ts源文件

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

import { User } from "../../models/user";

@Injectable()
export class GithubUsersProvider {
  githubApiUrl = 'api.github.com';

  constructor(public http: HttpClient) { 
    console.log("Hello Github Users service");
   }

  load(): Observable<User[]> {
    return this.http.get(`${this.githubApiUrl}/users`)
      .map(res => <User[]>res.json());
  }
}

我从控制台收到此错误

core.js:1449 ERROR Error: Uncaught (in promise): Error: StaticInjectorError(AppModule)[GithubUsersProvider -> HttpClient]: 
  StaticInjectorError(Platform: core)[GithubUsersProvider -> HttpClient]: 
    NullInjectorError: No provider for HttpClient!
Error: StaticInjectorError(AppModule)[GithubUsersProvider -> HttpClient]: 
  StaticInjectorError(Platform: core)[GithubUsersProvider -> HttpClient]: 
    NullInjectorError: No provider for HttpClient!
    at _NullInjector.get (core.js:1003)
    at resolveToken (core.js:1301)
    at tryResolveToken (core.js:1243)
    at StaticInjector.get (core.js:1111)
    at resolveToken (core.js:1301)
    at tryResolveToken (core.js:1243)
    at StaticInjector.get (core.js:1111)
    at resolveNgModuleDep (core.js:10896)
    at _createClass (core.js:10933)
    at _createProviderInstance$1 (core.js:10907)
    at _NullInjector.get (core.js:1003)
    at resolveToken (core.js:1301)
    at tryResolveToken (core.js:1243)
    at StaticInjector.get (core.js:1111)
    at resolveToken (core.js:1301)
    at tryResolveToken (core.js:1243)
    at StaticInjector.get (core.js:1111)
    at resolveNgModuleDep (core.js:10896)
    at _createClass (core.js:10933)
    at _createProviderInstance$1 (core.js:10907)
    at c (polyfills.js:3)
    at Object.reject (polyfills.js:3)
    at NavControllerBase._fireError (nav-controller-base.js:223)
    at NavControllerBase._failed (nav-controller-base.js:216)
    at nav-controller-base.js:263
    at t.invoke (polyfills.js:3)
    at Object.onInvoke (core.js:4760)
    at t.invoke (polyfills.js:3)
    at r.run (polyfills.js:3)
    at polyfills.js:3

标签： angularhttpionic-frameworkionic3

解决方案

您需要在导入下将 HttpClientModule 导入您的 app.module.ts

imports:[
  HttpClientModule
]

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