在 android 中获取位置无法在较新的设备上运行

Question

我正在尝试在我的项目中找到当前位置。所以我找到了这篇文章：

What is the simplest and most robust way to get the user's current location on Android?

我尝试使用locationclient但对结果不满意。我使用的代码如下：

Mylocation.java 类：

package com.igloo.classes;

import java.util.Timer;
import java.util.TimerTask;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;

public class MyLocation {
    Timer timer1;
    LocationManager lm;
    LocationResult locationResult;
    boolean gps_enabled=false;
    boolean network_enabled=false;


    public boolean getLocation(Context context, LocationResult result)
    {
        //I use LocationResult callback class to pass location value from MyLocation to user code.
        locationResult=result;
        if(lm==null)
            lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);

        //exceptions will be thrown if provider is not permitted.
        try{gps_enabled=lm.isProviderEnabled(LocationManager.GPS_PROVIDER);}catch(Exception ex){}
        try{network_enabled=lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);}catch(Exception ex){}

        //don't start listeners if no provider is enabled
        if(!gps_enabled && !network_enabled)
            return false;

        if(gps_enabled)
            lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListenerGps);
        if(network_enabled)
            lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListenerNetwork);
        timer1=new Timer();
        timer1.schedule(new GetLastLocation(), 90000);
        return true;
    }

    LocationListener locationListenerGps = new LocationListener() {
        public void onLocationChanged(Location location) {
            timer1.cancel();
            locationResult.gotLocation(location);
            lm.removeUpdates(this);
            lm.removeUpdates(locationListenerNetwork);
        }
        public void onProviderDisabled(String provider) {}
        public void onProviderEnabled(String provider) {}
        public void onStatusChanged(String provider, int status, Bundle extras) {}
    };

    LocationListener locationListenerNetwork = new LocationListener() {
        public void onLocationChanged(Location location) {
            timer1.cancel();
            locationResult.gotLocation(location);
            lm.removeUpdates(this);
            lm.removeUpdates(locationListenerGps);
        }
        public void onProviderDisabled(String provider) {}
        public void onProviderEnabled(String provider) {}
        public void onStatusChanged(String provider, int status, Bundle extras) {}
    };

    class GetLastLocation extends TimerTask {
        @Override
        public void run() {
             lm.removeUpdates(locationListenerGps);
             lm.removeUpdates(locationListenerNetwork);

             Location net_loc=null, gps_loc=null;
             if(gps_enabled)
                 gps_loc=lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
             if(network_enabled)
                 net_loc=lm.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);

             //if there are both values use the latest one
             if(gps_loc!=null && net_loc!=null){
                 if(gps_loc.getTime()>net_loc.getTime())
                     locationResult.gotLocation(gps_loc);
                 else
                     locationResult.gotLocation(net_loc);
                 return;
             }

             if(gps_loc!=null){
                 locationResult.gotLocation(gps_loc);
                 return;
             }
             if(net_loc!=null){
                 locationResult.gotLocation(net_loc);
                 return;
             }
             locationResult.gotLocation(null);
        }
    }
    public void cancelTimer()
    {
        if(timer1!=null)
        {
         timer1.cancel();
         lm.removeUpdates(locationListenerGps);
         lm.removeUpdates(locationListenerNetwork);
        }
    }


    public static abstract class LocationResult{
        public abstract void gotLocation(Location location);
    }
}

我的主类中的代码：我使用了回调方法来获取位置对象。

locationResult = new LocationResult(){
            @Override
            public void gotLocation(Location location){
                if(location!=null)
                {
                current_latitude=location.getLatitude();
                current_longitude=location.getLongitude();
                }
                if(location!=null&&!isLocationRecieved)
                {
                    MarinaJobKeys.user_viewing_jobs=true;
                    isLocationRecieved=true;

                    Handler handler = new Handler(Looper.getMainLooper());
                    handler.post(new Runnable(){

                        @Override
                        public void run() {
                            setcurrentlocation();

                        } 

                    });


                }
                else if(location==null)
                {
                    Toast.makeText(getActivity(),"NULL LOCATION RETURNED",Toast.LENGTH_LONG).show();
                }

            }

        };





 myLocation = new MyLocation();
            myLocation.getLocation(getActivity(), locationResult);

问题是这样的：

代码在旧设备上运行良好。但是当我在新设备上运行时，Mylocation 类中的 onLocationchanged 方法永远不会被调用。但在旧设备中它会立即被调用。我该如何解决这个问题？

编辑：问题在重新启动设备时得到解决。但是为什么会发生呢？

Answer 1

您必须从设置中启用位置。

请查看this link。

go to setting --> Location Access --> turn on Location.