发布应用程序时出现错误。 错误是属性json在类型对象上不存在

Question

当我尝试在Ionic serve命令中测试应用程序时，没有收到任何错误。 但是，当我尝试发布应用程序时，出现错误，因为“类型object上不存在属性json”。 该错误发生在转换阶段：

如何解决这个问题呢？ 我尝试了所有可能的方法，但是并没有解决我的问题。

Home.ts

import { Component } from '@angular/core';
import { NavController } from 'ionic-angular';
import { WeatherProvider } from '../../providers/weather/weather';
import { Storage } from '@ionic/storage';
//import { Response } from '@angular/http';
//import 'rxjs/add/operator/map';

@Component({
   selector: 'page-home',
   templateUrl: 'home.html'
})
export class HomePage {
   weather:any;
   location:{
        city:string,
        state:string
    }

   constructor(
      public navCtrl: NavController, 
      private weatherProvider:WeatherProvider,
      private storage: Storage) {

      }

      ionViewWillEnter(){
        this.storage.get('location').then((val)=>{
            if(val!=null){
                this.location = JSON.parse(val);
            }else{
                this.location = {
                    city: 'Chennai',
                    state: 'TN'
                }
            }


        this.weatherProvider.getWeather(this.location.city,this.location.state)
       // .map((res: Response) => res.json() )
            .subscribe(weather => {
                this.weather =  weather.current_observation;

        });

        });

      }

    }

天气

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

    @Injectable()
    export class WeatherProvider {
        apiKey = '6d3243fb22b01d0c';
        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());
        // .map((res: Response) => res.json() );

      }
    }

Answer 1

打字稿就是关于打字的。 因此，您应该声明从getWeather方法接收的对象的类型。 首先在home.ts的末尾创建一个Weather类（请看下面）

class Weather {
  current_observation: string;
}

并进行以下更改：

this.weatherProvider.getWeather(this.location.city,this.location.state)
       // .map((res: Response) => res.json() )
            .subscribe((weather: Weather) => {
                this.weather =  weather.current_observation;

        });
        });
      }

Answer 2

ionViewWillEnter（）{

this.storage.get('location').then((val) => {
  if(val != null){
    this.location = JSON.parse(val);
  } else{
    this.location ={
      city: 'miami',
      state: 'FL'
    }
  }

//尝试下面的代码this.weatherprovider.getweather（this.location.city，this.location.state）.subscribe（result => {let weather：any = result; this.weather = weather.current_observation; console.log（this .weather）;}）; }）; }