角離子：屬性“ json”在類型“對象”上不存在

Question

我正在創建一個顯示github用戶及其詳細信息的Ionic 2項目。 我創建了一個名為github-users.ts的服務文件，並通過.json（）方法向我展示了此錯誤。

類型“對象”上不存在屬性“ json”

這是我的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());
  }
}

我從控制台收到此錯誤

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

Answer 1

您需要在導入下將HttpClientModule導入到您的app.module.ts中

imports:[
  HttpClientModule
]

Answer 2

您的錯誤是= [沒有HttpClient的提供程序！]當您未在app.modules.ts文件中定義http模塊時，會發生這種類型的錯誤。 所以先檢查一下。

exp：從'@ angular / http'導入{HttpModule};

導入：[HttpModule]