json - Angular 5，rxjs 映射到 json，类型“对象”上不存在 'json'

Question

尝试关注在线视频，然后出现这个，我是 Angular 新手，其他解决方案对我没有帮助。

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

/*
  Generated class for the WeatherProvider provider.

  See https://angular.io/guide/dependency-injection for more info on providers
  and Angular DI.
*/
@Injectable()
export class WeatherProvider {
  apikey='7d2dc7a226a78c14';
  url;

  constructor(public http: HttpClient) {
    console.log('Hello WeatherProvider Provider');
    this.url='http://api.wunderground.com/api/'+this.apikey+'/conditions/q'
  }

    getWeather(city,state){
      return this.http.get(this.url+'/'+state+'/'+city+'.json')
        .map(res => res.json() );      
    }
}

Answer 1

如果您使用新的 HttpClient，则不需要解析 JSON，因为它会自动为您解码:

https://angular.io/guide/http#type-checking-the-response

The HttpClient.get() method parsed the JSON server response into the anonymous Object type. It doesn't know what the shape of that object is.

还有 https://angular.io/guide/http#requesting-non-json-data .