地理位置不是在Android的

Question

我试图通过openweathermap以获取天气信息的工作，问题是通过地理位置它没有显示任何数据，我测试我的应用程序在真实的设备，甚至是肯定的清单

mainactivity

许可

package com.example.vamshi.weathertest; 

import android.Manifest; 
import android.content.Context; 
import android.content.pm.PackageManager; 
import android.location.Criteria; 
import android.location.Location; 
import android.location.LocationManager; 
import android.support.v4.app.ActivityCompat; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.util.Log; 
import android.widget.TextView; 

public class MainActivity extends AppCompatActivity { 

    static TextView place; 
    static TextView temp; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     place = (TextView)findViewById(R.id.place); 
     temp = (TextView)findViewById(R.id.temp); 

     LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); 
     String provider = locationManager.getBestProvider(new Criteria(),false); 

     //Log.i("Jimmy",provider+" hi"); 
     if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) { 
      // TODO: Consider calling 
      // ActivityCompat#requestPermissions 
      // here to request the missing permissions, and then overriding 
      // public void onRequestPermissionsResult(int requestCode, String[] permissions, 
      //           int[] grantResults) 
      // to handle the case where the user grants the permission. See the documentation 
      // for ActivityCompat#requestPermissions for more details. 
      return; 
     } 
     Location location = locationManager.getLastKnownLocation(provider); 
     Log.i("Jimmy","hi "+location); 
     double lat = location.getLatitude(); 
     double lng = location.getLongitude(); 
     Weather getData = new Weather(); 
     getData.execute("http://api.openweathermap.org/data/2.5/weather?lat=" + String.valueOf(lat) + "&lon=" + String.valueOf(lng) + "&appid=3c70f7d8f9e272cd6f73036a65228391"); 


    } 
} 

如果我从网址中删除" + String.valueOf(lat) + "和" + String.valueOf(lng) + "他工作正常。

天气活动

package com.example.vamshi.weathertest; 

import android.os.AsyncTask; 

import org.json.JSONException; 
import org.json.JSONObject; 

import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.net.HttpURLConnection; 
import java.net.MalformedURLException; 
import java.net.URL; 

/** 
* Created by Vamshi on 5/14/2017. 
*/ 

public class Weather extends AsyncTask<String,Void,String> { 

    String result; 
    @Override 
    protected String doInBackground(String... urls) { 
     result = ""; 
     URL link; 
     HttpURLConnection myconnection = null; 

     try { 
      link = new URL(urls[0]); 
      myconnection = (HttpURLConnection)link.openConnection(); 
      InputStream in = myconnection.getInputStream(); 
      InputStreamReader myStreamReader = new InputStreamReader(in); 
      int data = myStreamReader.read(); 
      while(data!= -1){ 
       char current = (char)data; 
       result+= current; 
       data = myStreamReader.read(); 
      } 
      return result; 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 

     return null; 
    } 

    @Override 
    protected void onPostExecute(String s) { 
     super.onPostExecute(s); 

     try { 
      JSONObject myObject = new JSONObject(result); 
      JSONObject main = new JSONObject(myObject.getString("main")); 
      String temperature = main.getString("temp"); 
      String placeName = myObject.getString("name"); 

      MainActivity.place.setText(placeName); 
      MainActivity.temp.setText(temperature); 
     } catch (JSONException e) { 
      e.printStackTrace(); 
     } 
    } 
} 

Answer 1

编辑

getData.execute("http://api.openweathermap.org/data/2.5/weather?lat=" + 
    String.valueOf(lat) + "&lon=" + String.valueOf(lng) + 
    "&appid=3c70f7d8f9e272cd6f73036a65228391"); 

要

getData.execute("http://api.openweathermap.org/data/2.5/weather?lat=" + 
    lat + "&lon=" + lng + "&appid=3c70f7d8f9e272cd6f73036a65228391");