Question

我需要在点击按钮时使用NETWORK_PROVIDER获取当前位置。如果网络不可用，我想使用GPS_PROVIDER获取位置。我怎么能这样做？

Answer 1

这就是我在做的事情：

MyLocation类：

import android.app.ProgressDialog;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;

public class MyLocation {
   // Timer timer1;
    LocationManager lm;
    LocationResult locationResult;
    boolean gps_enabled=false;
    boolean network_enabled=false;
    AsyncTask<Context, Void, Void> mtask;

    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(), 20000);
        mtask= new GetLastLocation().execute();
        return true;
    }

    LocationListener locationListenerGps = new LocationListener() {
        public void onLocationChanged(Location location) {
           // timer1.cancel();
             mtask.cancel(true);
            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) {
           mtask.cancel(true);
            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) {}
    };

    private Context mContext;
    public MyLocation(Context c) { this.mContext = c; }


    class GetLastLocation extends AsyncTask<Context, Void, Void>
    {

    ProgressDialog dialog = new ProgressDialog(mContext);

        protected void onPreExecute()
        {
           dialog.setMessage("Searching....");
           dialog.show();
        }

        protected Void doInBackground(Context... params)
        {
          Handler mHandler = new Handler(Looper.getMainLooper());



                       // ...
                       mHandler.post(new Runnable() {
                         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);
                    }
                       });
                       // ...


            return null;
        }

        protected void onPostExecute(final Void unused)
        {
            dialog.dismiss();
        }
    }





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

和按钮点击的方法：

MyLocation myLocation = new MyLocation();
private void locationClick() {
myLocation.getLocation(this, locationResult));
}

public LocationResult locationResult = new LocationResult(){
@Override
public void gotLocation(final Location location){
    //Got the location!
    });
}
};

我在stackoverflow中发现了这个问题，当时我正在寻找类似问题的解决方案......

Answer 2

您已使用此方法检查所有启用提供程序

void requestLocationUpdates()
    {
        locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
        List<String> enabledProviders = this.locationManager.getProviders(true);
        for (String provider:enabledProviders){
            Log.i(">>>>>>>", "Requesting location updates from provider " + provider);
            this.locationManager.requestLocationUpdates(provider, 10000l, 10, this);
        }
    }

Answer 3

  LocationManager locMgr = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
    LocationListener locListner = new LocationListener() {

        public void onProviderEnabled(String provider) {


        }

        public void onProviderDisabled(String provider) {


        }

        public void onLocationChanged(Location location) {

            // CODE TO READ LOCATION

        }

        public void onStatusChanged(String provider, int status,
                Bundle extras) {
            // TODO Auto-generated method stub

        }
    };

    // ON Click of button  do this request.
    locMgr.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locListner);

您还需要在清单文件中添加权限

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

有关详细信息，请参阅Developer Guide

单击具有默认提供程序的按钮获取位置

3 个答案: