无法从全球定位系统定位？

Question

我试图从全球定位系统获得位置，但无法得到它。这是因为该位置由网络提供程序访问。

如果我正在注释网络提供者的所有代码，那么GPS位置返回null。

我试了这么多，但解决不了这个问题。

如果有人能帮忙，那对我将是很大的帮助。

我正在使用这个链接作为参考。

https://stackoverflow.com/a/3145655/1395259

这是我的代码：

MainActivity.java

package com.example.locationsimple;

import com.example.locationsimple.MyLocation.LocationResult;

import android.location.Location;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

    TextView textView;
    LocationResult locationResult;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView = (TextView) findViewById(R.id.textViewLocation);
        Button button = (Button) findViewById(R.id.button);
        button.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                locationResult = new LocationResult(){

                    @Override
                    public void gotLocation(Location location) {

                        while(true)
                        {
                            Log.i("Log", "Inside while loop ");

                            if(location != null)
                            {
                                Log.i("Log", "Here the location is not null");
                                if(location.getLatitude() !=0.0 || location.getLongitude() != 0.0)
                                {
                                    if(location.getAccuracy() < 100)
                                    {
                                        Log.i("Log", "Inside while loop BREAKS");

                                        try
                                        {
                                            String loc = "Lattitude: "+location.getLatitude()+"  longi  "+location.getLongitude()+"  Accur "+location.getAccuracy()+"  Time "+location.getTime();
                                            Log.i("Log",loc);
                                            Toast.makeText(MainActivity.this, ""+loc, Toast.LENGTH_LONG).show();
                                            textView.setText(loc);
                                        }
                                        catch (Exception e) {
                                            // TODO: handle exception
                                            e.printStackTrace();
                                        }

                                        break;
                                    }
                                    else
                                    {
                                        Log.i("Log", "no Accuracy");
                                        Log.i("Log", "latti"+location.getLatitude()+"  Longi "+location.getLongitude()+"  Accur "+location.getAccuracy()+location.getProvider());                                       
                                        break;
                                    }
                                }
                            }
                            else
                            {
                                Log.i("Log", "Here got the location is null");
                                break;
                            }
                        }
                        //textView.setText(location.getLatitude()+"::"+location.getLongitude()+"::"+location.getAccuracy()+" Provider  "+location.getProvider());                                               
                    }
                };
                MyLocation myLocation = new MyLocation();
                myLocation.getLocation(MainActivity.this, locationResult);              
                }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

}

MyLocation.java

package com.example.locationsimple;

import java.util.Timer;
import java.util.TimerTask;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.provider.Settings;

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

    public boolean getLocation(Context context, LocationResult result)
    {
        mContext = context;
        //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);
            /*Criteria criteria = new Criteria();
            criteria.setAccuracy(Criteria.ACCURACY_HIGH);  
            lm.getBestProvider(criteria, true);*/
        //exceptions will be thrown if provider is not permitted.
        try
            {
                gps_enabled=lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
            }
        catch(Exception ex)
        {
            ex.printStackTrace();
        }
        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)
        {
            showSettingsAlert();
            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(), 30000);
        return true;
    }
    public void showSettingsAlert(){


        AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

        alertDialog.setCancelable(false);
        // Setting Dialog Title
        alertDialog.setTitle("GPS Is Not Enabled");


        // Setting Dialog Message
        alertDialog.setMessage("Please Enabled Wireless Network And GPS");

        // On pressing Settings button
        alertDialog.setNeutralButton("OK", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int which) {
                dialog.cancel();
                Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                mContext.startActivity(intent);
            }
        });

        // Showing Alert Message
        alertDialog.show();
    }

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

谢谢..

Answer 1

您可以使用下面的服务使gps.just在开始时调用此服务。

公共类MyService扩展服务{

LocationManager locationManager;
@Override
public void onCreate() {

    //

        // TODO Auto-generated method stub

        String context = Context.LOCATION_SERVICE;
        locationManager = (LocationManager) getSystemService(context);  

        /** Criteria for selecting best provider */

        Criteria criteria = new Criteria();
        criteria.setAccuracy(Criteria.ACCURACY_FINE);
        criteria.setAltitudeRequired(false);
        criteria.setBearingRequired(false);
        criteria.setCostAllowed(true);
        criteria.setPowerRequirement(Criteria.POWER_LOW);

        /** Passing criteria and select only enabled provider */
        String provider = locationManager.getBestProvider(criteria, true);
        Location location = locationManager.getLastKnownLocation(provider);
        /** calls the Location Listner */
        locationManager.requestLocationUpdates(provider, 500, 0,locationListener);
    }

    private final LocationListener locationListener = new LocationListener() {
        public void onLocationChanged(Location location) {
            updateWithNewLocation(location);
        }

        public void onProviderDisabled(String provider) {
            updateWithNewLocation(null);
        }

        public void onProviderEnabled(String provider) {
        }

        public void onStatusChanged(String provider, int status, Bundle extras) {
        }
    };

    private void updateWithNewLocation(Location location) 
    {

        System.out.println("+++++++++++++++++++SASI+++++++++++++++++++++++++++++++++++++++++");
        String latLongString, addressString = null;
        double lat = 0, lng = 0;
        if (location != null) {
            lat = location.getLatitude();
            lng = location.getLongitude();
            //latLongString = "Lat:" + lat + "\nLong: " + lng;

            /** Getting Address */


        } else {
            latLongString = "No location found";
            addressString = "No location found";
        }
        //System.out.println("@@@@@@@@@@@" + addressString + lat + lng);
        SearchDeals.latPoint=location.getLatitude();
        SearchDeals.lngPoint=location.getLongitude();




        Deals_route.sourcelati=location.getLatitude();
        Deals_route.sourcelong=location.getLongitude();

    }




@Override
public void onDestroy() {

    super.onDestroy();

    //

    //Toast.makeText(this, "GPS Service Destroyed", Toast.LENGTH_LONG).show();

    locationManager.removeUpdates(locationListener);

    System.out.println("@@@@@@@@@@@ inside ONDESTROY GPS listener removed");

}

@Override
public int onStartCommand(Intent intent, int flags, int startId)

{

    //

    Log.v("StartServiceAtBoot", "StartAtBootService -- onStartCommand()");

    //Toast.makeText(this, "Service started", Toast.LENGTH_LONG).show();

    // We want this service to continue running until it is explicitly

    // stopped, so return sticky.

    return START_STICKY;

}  




@Override
public IBinder onBind(Intent intent) {
    // TODO Auto-generated method stub
    return null;
}

}

Answer 2

我刚刚在我的设备上测试了上面的代码，一切都很顺利，不知道你的终端出了什么问题。

重要注释：

• 请确保您拥有进入清单文件中GPS位置的权限。

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

• 代码可能无法在模拟器上正常工作，更好地在实际设备上进行测试。如果您没有访问权限，请查看DMMS仿真程序控制以生成位置数据。

编辑：

您需要提交与网络提供商相关的位置数据。

并从textView.setText对象中删除textView，因为textView为null。所以解决办法是：

getLocation(Location location) {
.........
String loc = "Lattitude: "+location.getLatitude()+"  longi  "+location.getLongitude()+"  Accur "+location.getAccuracy()+"  Time "+location.getTime() +" "+location.getProvider();

Log.i("Log",loc);
Toast.makeText(MainActivity.this, loc, Toast.LENGTH_LONG).show();
}

并注释掉MyLocation类中的网络代码。

 // if(network_enabled)

// lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER，0，0，locationListenerNetwork)；