Android上的LocationManager API似乎对一个只需要偶尔粗略估计用户位置的应用程序来说有点麻烦。

我正在开发的应用程序本身并不是一个定位应用程序,但它确实需要获取用户的位置,以便显示附近企业的列表。它不需要担心用户是否在移动或类似的事情。

以下是我想做的:

向用户显示附近位置的列表。预加载用户的位置,以便在“活动X”中需要它时,它将可用。我并不特别关心更新的准确性或频率。只要不太远,只要抓住一个位置就足够了。也许如果我想变得更漂亮,我会每隔几分钟左右更新一次位置,但这不是一个很大的优先事项。适用于任何具有GPS或网络位置提供商的设备。

这似乎并不难,但在我看来,我必须组建两个不同的位置提供商(GPS和NETWORK),并管理每个提供商的生命周期。不仅如此,我还必须在多个活动中复制相同的代码以满足#2。过去,我曾尝试使用getBestProvider()将解决方案简化为仅使用一个位置提供程序,但这似乎只提供了最好的“理论”提供程序,而不是实际会为您提供最佳结果的提供程序。

有没有更简单的方法来实现这一点?


当前回答

我已经创建了一个小应用程序,并逐步描述以获取当前位置GPS坐标。

以下URL中的完整示例源代码:


获取当前位置坐标,城市名称-在Android中


查看其工作原理:

我们只需要在清单文件中添加此权限<uses permission android:name=“android.permission.ACCESS_FINE_LOCATION”></使用权限>并像这样创建LocationManager实例LocationManager LocationManager=(LocationManager)getSystemService(Context.LOCATION_SERVICE);检查GPS是否已启用然后实现LocationListener和Get CoordinatesLocationListener LocationListener=新的MyLocationListeners();locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,5000,10,locationListener);下面是要做的示例代码


/*----------Listener class to get coordinates ------------- */
private class MyLocationListener implements LocationListener {

    @Override
    public void onLocationChanged(Location loc) {
        editLocation.setText("");
        pb.setVisibility(View.INVISIBLE);
        Toast.makeText(
            getBaseContext(),
            "Location changed: Lat: " + loc.getLatitude() + " Lng: "
                + loc.getLongitude(), Toast.LENGTH_SHORT).show();
        String longitude = "Longitude: " + loc.getLongitude();
        Log.v(TAG, longitude);
        String latitude = "Latitude: " + loc.getLatitude();
        Log.v(TAG, latitude);
        /*-------to get City-Name from coordinates -------- */
        String cityName = null;
        Geocoder gcd = new Geocoder(getBaseContext(), Locale.getDefault());
        List<Address> addresses;
        try {
            addresses = gcd.getFromLocation(loc.getLatitude(),
                loc.getLongitude(), 1);
            if (addresses.size() > 0)
                System.out.println(addresses.get(0).getLocality());
            cityName = addresses.get(0).getLocality();
        } catch (IOException e) {
            e.printStackTrace();
        }
        String s = longitude + "\n" + latitude + "\n\nMy Current City is: "
            + cityName;
        editLocation.setText(s);
    }

    @Override
    public void onProviderDisabled(String provider) {}

    @Override
    public void onProviderEnabled(String provider) {}

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

其他回答

编辑:更新了Google Play Services库中的最新位置服务API(2014年7月)

我建议您使用新的位置服务API,该API可从Google Play Services库中获得,它提供了一个更强大的高级框架,可自动执行位置提供商选择和电源管理等任务。根据官方文档:“……位置API使您可以轻松地构建位置感知应用程序,而无需关注底层位置技术的细节。它们还允许您通过使用设备硬件的所有功能来最小化功耗。”

有关更多信息,请访问:使您的应用程序位置感知

要查看使用最新位置服务API的完整示例,请访问:Android LocationClient类已弃用,但在文档中使用

通过使用FusedLocationProviderApi,这是最新的API,也是在Android中获取位置的最佳可能性。将其添加到build.gradle文件中

dependencies {
    compile 'com.google.android.gms:play-services:6.5.87'
}

您可以通过此url获取完整的源代码http://javapapers.com/android/android-location-fused-provider/

尽管这里已经给出了答案。我只是想向全世界分享这一点,以防遇到这种情况。

我的要求是,我需要在最长30到35秒内获取用户的当前位置,所以下面是我根据Nirav Ranpara的回答制定的解决方案。

1.我制作了MyLocationManager.java类,该类处理所有GPS和网络内容

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import com.app.callbacks.OnLocationDetectectionListener;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.provider.Settings;
import android.util.Log;
import android.widget.Toast;

public class MyLocationManager {
    /** The minimum distance to GPS change Updates in meters **/
    private final long MIN_DISTANCE_CHANGE_FOR_UPDATES_FOR_GPS = 2; // 2
                                                                    // meters
    /** The minimum time between GPS updates in milliseconds **/
    private final long MIN_TIME_BW_UPDATES_OF_GPS = 1000 * 5 * 1; // 5
                                                                    // seconds

    /** The minimum distance to NETWORK change Updates in meters **/
    private final long MIN_DISTANCE_CHANGE_FOR_UPDATES_FOR_NETWORK = 5; // 5
                                                                        // meters
    /** The minimum time between NETWORK updates in milliseconds **/
    private final long MIN_TIME_BW_UPDATES_OF_NETWORK = 1000 * 10 * 1; // 10
                                                                        // seconds

    /**
     * Lets just say i don't trust the first location that the is found. This is
     * to avoid that
     **/

    private int NetworkLocationCount = 0, GPSLocationCount = 0;
    private boolean isGPSEnabled;
    private boolean isNetworkEnabled;
    /**
     * Don't do anything if location is being updated by Network or by GPS
     */
    private boolean isLocationManagerBusy;
    private LocationManager locationManager;
    private Location currentLocation;
    private Context mContext;
    private OnLocationDetectectionListener mListener;

    public MyLocationManager(Context mContext,
            OnLocationDetectectionListener mListener) {
        this.mContext = mContext;
        this.mListener = mListener;
    }

    /**
     * Start the location manager to find my location
     */
    public void startLocating() {
        try {
            locationManager = (LocationManager) mContext
                    .getSystemService(Context.LOCATION_SERVICE);

            // Getting GPS status
            isGPSEnabled = locationManager
                    .isProviderEnabled(LocationManager.GPS_PROVIDER);

            // Getting network status
            isNetworkEnabled = locationManager
                    .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

            if (!isGPSEnabled && !isNetworkEnabled) {
                // No network provider is enabled
                showSettingsAlertDialog();
            } else {
                // If GPS enabled, get latitude/longitude using GPS Services
                if (isGPSEnabled) {
                    locationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES_OF_GPS,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES_FOR_GPS,
                            gpsLocationListener);

                }
                if (isNetworkEnabled) {
                    locationManager.requestLocationUpdates(
                            LocationManager.NETWORK_PROVIDER,
                            MIN_TIME_BW_UPDATES_OF_NETWORK,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES_FOR_NETWORK,
                            networkLocationListener);

                }
            }
            /**
             * My 30 seconds plan to get myself a location
             */
            ScheduledExecutorService se = Executors
                    .newSingleThreadScheduledExecutor();
            se.schedule(new Runnable() {

                @Override
                public void run() {
                    if (currentLocation == null) {
                        if (isGPSEnabled) {
                            currentLocation = locationManager
                                    .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                        } else if (isNetworkEnabled) {
                            currentLocation = locationManager
                                    .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);

                        }
                        if (currentLocation != null && mListener != null) {
                            locationManager.removeUpdates(gpsLocationListener);
                            locationManager
                                    .removeUpdates(networkLocationListener);
                            mListener.onLocationDetected(currentLocation);
                        }
                    }
                }
            }, 30, TimeUnit.SECONDS);

        } catch (Exception e) {
            Log.e("Error Fetching Location", e.getMessage());
            Toast.makeText(mContext,
                    "Error Fetching Location" + e.getMessage(),
                    Toast.LENGTH_SHORT).show();
        }
    }

    /**
     * Handle GPS location listener callbacks
     */
    private LocationListener gpsLocationListener = new LocationListener() {

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

        }

        @Override
        public void onProviderEnabled(String provider) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onProviderDisabled(String provider) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onLocationChanged(Location location) {

            if (GPSLocationCount != 0 && !isLocationManagerBusy) {
                Log.d("GPS Enabled", "GPS Enabled");
                isLocationManagerBusy = true;
                currentLocation = location;
                locationManager.removeUpdates(gpsLocationListener);
                locationManager.removeUpdates(networkLocationListener);
                isLocationManagerBusy = false;
                if (currentLocation != null && mListener != null) {
                    mListener.onLocationDetected(currentLocation);
                }
            }
            GPSLocationCount++;
        }
    };
    /**
     * Handle Network location listener callbacks
     */
    private LocationListener networkLocationListener = new LocationListener() {

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

        }

        @Override
        public void onProviderEnabled(String provider) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onProviderDisabled(String provider) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onLocationChanged(Location location) {
            if (NetworkLocationCount != 0 && !isLocationManagerBusy) {
                Log.d("Network", "Network");
                isLocationManagerBusy = true;
                currentLocation = location;
                locationManager.removeUpdates(gpsLocationListener);
                locationManager.removeUpdates(networkLocationListener);
                isLocationManagerBusy = false;
                if (currentLocation != null && mListener != null) {
                    mListener.onLocationDetected(currentLocation);
                }
            }
            NetworkLocationCount++;
        }
    };

    /**
     * Function to show settings alert dialog. On pressing the Settings button
     * it will launch Settings Options.
     * */
    public void showSettingsAlertDialog() {
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

        // Setting Dialog Title
        alertDialog.setTitle("GPS is settings");

        // Setting Dialog Message
        alertDialog
                .setMessage("GPS is not enabled. Do you want to go to settings menu?");

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

        // On pressing the cancel button
        alertDialog.setNegativeButton("Cancel",
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.cancel();
                    }
                });

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

2.我创建了一个接口(回调)OnLocationDetectionListener.java,以便将结果传递回调用片段或活动

import android.location.Location;

public interface OnLocationDetectectionListener {
    public void onLocationDetected(Location mLocation);
}

3.然后我制作了一个MainAppActivty.java Activity,它实现了OnLocationDetectionListener接口,下面是我如何在其中接收位置

public class MainAppActivty extends Activity implements
        OnLocationDetectectionListener {

    private Location currentLocation;
    private MyLocationManager mLocationManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        setContentView(R.layout.activity_home);
        super.onCreate(savedInstanceState);
            mLocationManager = new MyLocationManager(this, this);
            mLocationManager.startLocating();
    }

    @Override
    public void onLocationDetected(Location mLocation) {
        //Your new Location is received here
        currentLocation = mLocation;
    }

4.将以下权限添加到清单文件

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

希望这对其他人有帮助:)

其中一些人现在已经过时了,所以我回答说,

FusedLocationProviderClient fusedLocationProviderClient; //set global variable
Location currentLocation;//set global var
private boolean mLocationPermissionGranted; //set global var
 fusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(getContext()); //write this oncreate
        fetchLastLocation();  // call the funct for current location
//here is the function
private void fetchLastLocation() {

    if (ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_FINE_LOCATION)
            != PackageManager.PERMISSION_GRANTED) {

        ActivityCompat.requestPermissions(getActivity(),new String[]{
                Manifest.permission.ACCESS_FINE_LOCATION},REQUEST_CODE);
        return;
    }else {
        mLocationPermissionGranted=true;
    }
    Task<Location> task= fusedLocationProviderClient.getLastLocation();
    task.addOnSuccessListener(new OnSuccessListener<Location>() {
        @Override
        public void onSuccess(Location location) {
            if(location != null){
                currentLocation =location;
               Toast.makeText(getContext(), currentLocation.getLatitude()+"" +
                        " "+currentLocation.getLongitude(), 
                   Toast.LENGTH_SHORT).show();
//if you want to show in google maps
                SupportMapFragment supportMapFragment =(SupportMapFragment)
                        getChildFragmentManager().findFragmentById(R.id.map);
                supportMapFragment.getMapAsync(MapsFragment.this);
            }
        }
    });


}

在搜索了如何获得最佳精确用户位置的最佳实现后,我成功地结合了所有最佳方法,并提出了以下类:

/**
 * Retrieve accurate location from GPS or network services. 
 * 
 *
 * Class usage example:
 * 
 * public void onCreate(Bundle savedInstanceState) {
 *      ...
 *      my_location = new MyLocation();
 *      my_location.init(main.this, locationResult);
 * }
 * 
 * 
 * public LocationResult locationResult = new LocationResult(){
 *      @Override
 *      public void gotLocation(final Location location){
 *          // do something
 *          location.getLongitude();
 *          location.getLatitude();
 *      }
 *  };
 */
class MyLocation{

    /**
     * If GPS is enabled. 
     * Use minimal connected satellites count.
     */
    private static final int min_gps_sat_count = 5;

    /**
     * Iteration step time.
     */
    private static final int iteration_timeout_step = 500;

    LocationResult locationResult;
    private Location bestLocation = null;
    private Handler handler = new Handler();
    private LocationManager myLocationManager; 
    public Context context;

    private boolean gps_enabled = false;

    private int counts    = 0;
    private int sat_count = 0;

    private Runnable showTime = new Runnable() {
    
         public void run() {
            boolean stop = false;
            counts++;
            System.println("counts=" + counts);
            
            //if timeout (1 min) exceeded, stop tying
            if(counts > 120){
                stop = true;
            }
            
            //update last best location
            bestLocation = getLocation(context);
            
            //if location is not ready or don`t exists, try again
            if(bestLocation == null && gps_enabled){
                System.println("BestLocation not ready, continue to wait");
                handler.postDelayed(this, iteration_timeout_step);
            }else{
                //if best location is known, calculate if we need to continue to look for better location
                //if gps is enabled and min satellites count has not been connected or min check count is smaller then 4 (2 sec)  
                if(stop == false && !needToStop()){
                    System.println("Connected " + sat_count + " sattelites. continue waiting..");
                    handler.postDelayed(this, iteration_timeout_step);
                }else{
                    System.println("#########################################");
                    System.println("BestLocation found return result to main. sat_count=" + sat_count);
                    System.println("#########################################");

                    // removing all updates and listeners
                    myLocationManager.removeUpdates(gpsLocationListener);
                    myLocationManager.removeUpdates(networkLocationListener);    
                    myLocationManager.removeGpsStatusListener(gpsStatusListener);
                    sat_count = 0;
                    
                    // send best location to locationResult
                    locationResult.gotLocation(bestLocation);
                }
            }
         }
    };
        
    /**
     * Determine if continue to try to find best location
     */
    private Boolean needToStop(){

        if(!gps_enabled){
                          return true;
                     }
          else if(counts <= 4){
                return false;
            }
            if(sat_count < min_gps_sat_count){
                //if 20-25 sec and 3 satellites found then stop
                if(counts >= 40 && sat_count >= 3){
                    return true;
                }
                return false;
            }
        }
        return true;
    }

    /**
     * Best location abstract result class
     */
    public static abstract class LocationResult{
         public abstract void gotLocation(Location location);
     }

    /**
     * Initialize starting values and starting best location listeners
     * 
     * @param Context ctx
     * @param LocationResult result
     */
    public void init(Context ctx, LocationResult result){
        context = ctx;
        locationResult = result;
    
        myLocationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
    
        gps_enabled = (Boolean) myLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
    
        bestLocation = null;
        counts = 0;
    
        // turning on location updates
        myLocationManager.requestLocationUpdates("network", 0, 0, networkLocationListener);
        myLocationManager.requestLocationUpdates("gps", 0, 0, gpsLocationListener);
        myLocationManager.addGpsStatusListener(gpsStatusListener);
    
        // starting best location finder loop
        handler.postDelayed(showTime, iteration_timeout_step);
    }

    /**
     * GpsStatus listener. OnChainged counts connected satellites count.
     */
    public final GpsStatus.Listener gpsStatusListener = new GpsStatus.Listener() {
        public void onGpsStatusChanged(int event) {
        
             if(event == GpsStatus.GPS_EVENT_SATELLITE_STATUS){
                try {
                    // Check number of satellites in list to determine fix state
                     GpsStatus status = myLocationManager.getGpsStatus(null);
                     Iterable<GpsSatellite>satellites = status.getSatellites();
                     
                     sat_count = 0;
                     
                     Iterator<GpsSatellite>satI = satellites.iterator();
                     while(satI.hasNext()) {
                         GpsSatellite satellite = satI.next();
                         System.println("Satellite: snr=" + satellite.getSnr() + ", elevation=" + satellite.getElevation());                         
                         sat_count++;
                     }
                } catch (Exception e) {
                    e.printStackTrace();
                    sat_count = min_gps_sat_count + 1;
                }
                 
                 System.println("#### sat_count = " + sat_count);
             }
         }
    };

    /**
     * Gps location listener.
     */
    public final LocationListener gpsLocationListener = new LocationListener(){
        @Override
         public void onLocationChanged(Location location){
        
        }
         public void onProviderDisabled(String provider){}
         public void onProviderEnabled(String provider){}
         public void onStatusChanged(String provider, int status, Bundle extras){}
    }; 

    /**
     * Network location listener.
     */
    public final LocationListener networkLocationListener = new LocationListener(){
        @Override
         public void onLocationChanged(Location location){
        
        }
         public void onProviderDisabled(String provider){}
         public void onProviderEnabled(String provider){}
         public void onStatusChanged(String provider, int status, Bundle extras){}
    }; 


    /**
     * Returns best location using LocationManager.getBestProvider()
     * 
     * @param context
     * @return Location|null
     */
    public static Location getLocation(Context context){
        System.println("getLocation()");
    
        // fetch last known location and update it
        try {
            LocationManager lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
             
            Criteria criteria = new Criteria();
            criteria.setAccuracy(Criteria.ACCURACY_FINE);
             criteria.setAltitudeRequired(false);
             criteria.setBearingRequired(false);
             criteria.setCostAllowed(true);
             String strLocationProvider = lm.getBestProvider(criteria, true);
            
             System.println("strLocationProvider=" + strLocationProvider);
             Location location = lm.getLastKnownLocation(strLocationProvider);
             if(location != null){
                return location;
             }
             return null;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
}

如果启用gps,此类将尝试连接到min_gps_sat_count卫星。Else返回LocationManager.getBestProvider()位置。检查代码!