在Android上獲取用戶當前位置的最簡單,最可靠的方法是什麼?

Android上的LocationManager API彷佛對於只須要偶爾粗略估計用戶位置的應用程序來講有點麻煩。 android

我正在使用的應用程序自己並非真正的位置應用程序,可是它確實須要獲取用戶的位置才能顯示附近商家的列表。 無需擔憂用戶是否四處走動或相似的事情。 git

這是我想作的: canvas

  1. 向用戶顯示附近位置的列表。
  2. 預加載用戶的位置,以便在Activity X中須要時可使用它。
  3. 我並不特別在意準確性或更新頻率。 只要抓住一個位置就足夠了,只要它不遠便可。 也許若是我想花哨的話,我會每隔幾分鐘左右更新一次位置,但這並非一個重要的優先事項。
  4. 只要具備GPS或網絡位置提供程序的任何設備便可使用。

彷佛不該該那麼難,可是在我看來,我不得不啓動兩個不一樣的位置提供程序(GPS和網絡)並管理每一個生命週期。 不只如此,我還必須在多個活動中重複相同的代碼才能知足#2的要求。 過去我曾嘗試使用getBestProvider()將解決方案縮減爲僅使用一個位置提供程序,但這彷佛只爲您提供最佳的「理論」提供程序,而不是實際上會爲您提供最佳結果的提供程序。 api

有沒有更簡單的方法能夠作到這一點? 網絡


#1樓

使用如下代碼,它將爲您提供最佳的提供程序: ide

String locCtx = Context.LOCATION_SERVICE; 

LocationManager locationMgr = (LocationManager) ctx.getSystemService(locCtx);

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

String provider = locationMgr.getBestProvider(criteria, true);

System.out.println("Best Available provider::::"+provider);

#2樓

我建立了一個帶有逐步說明的小型應用程序,以獲取當前位置的GPS座標。 post

在此處輸入圖片說明

如下網址中包含完整的示例源代碼: fetch


獲取當前位置座標,城市名稱-在Android中 ui


看看它怎麼運做 : this

  • 咱們要作的就是在清單文件中添加此權限

    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"> </uses-permission>
  • 並像這樣建立LocationManager實例

    LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
  • 檢查GPS是否啓用

  • 而後實現LocationListener和獲取座標

    LocationListener locationListener = new MyLocationListener(); locationManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 5000, 10, locationListener);
  • 這是示例代碼


/*----------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) {}
}

#3樓

這是提供用戶當前位置的代碼

建立地圖活動:

public class Maps extends MapActivity {

    public static final String TAG = "MapActivity";
    private MapView mapView;
    private LocationManager locationManager;
    Geocoder geocoder;
    Location location;
    LocationListener locationListener;
    CountDownTimer locationtimer;
    MapController mapController;
    MapOverlay mapOverlay = new MapOverlay();

    @Override
    protected void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.main);
        initComponents();
        mapView.setBuiltInZoomControls(true);
        mapView.setSatellite(true);
        mapView.setTraffic(true);
        mapView.setStreetView(true);
        mapController = mapView.getController();
        mapController.setZoom(16);
        locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
        if (locationManager == null) {
            Toast.makeText(Maps.this, "Location Manager Not Available",
                Toast.LENGTH_SHORT).show();
            return;
        }
        location = locationManager
                .getLastKnownLocation(LocationManager.GPS_PROVIDER);
        if (location == null)
            location = locationManager
                    .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
        if (location != null) {
            double lat = location.getLatitude();
            double lng = location.getLongitude();
            Toast.makeText(Maps.this, "Location Are" + lat + ":" + lng,
                Toast.LENGTH_SHORT).show();
            GeoPoint point = new GeoPoint((int) (lat * 1E6), (int) (lng * 1E6));
            mapController.animateTo(point, new Message());
            mapOverlay.setPointToDraw(point);
            List<Overlay> listOfOverlays = mapView.getOverlays();
            listOfOverlays.clear();
            listOfOverlays.add(mapOverlay);
        }
        locationListener = new LocationListener() {

            public void onStatusChanged(String arg0, int arg1, Bundle arg2) {}

            public void onProviderEnabled(String arg0) {}

            public void onProviderDisabled(String arg0) {}

            public void onLocationChanged(Location l) {
                location = l;
                locationManager.removeUpdates(this);
                if (l.getLatitude() == 0 || l.getLongitude() == 0) {
                } else {
                    double lat = l.getLatitude();
                    double lng = l.getLongitude();
                    Toast.makeText(Maps.this, "Location Are" + lat + ":" + lng,
                        Toast.LENGTH_SHORT).show();
                }
            }
        };
        if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER))
            locationManager.requestLocationUpdates(
                LocationManager.GPS_PROVIDER, 1000, 10f, locationListener);
        locationManager.requestLocationUpdates(
            LocationManager.NETWORK_PROVIDER, 1000, 10f, locationListener);
        locationtimer = new CountDownTimer(30000, 5000) {

            @Override
            public void onTick(long millisUntilFinished) {
                if (location != null) locationtimer.cancel();
            }

            @Override
            public void onFinish() {
                if (location == null) {
                }
            }
        };
        locationtimer.start();
    }

    public MapView getMapView() {
        return this.mapView;
    }

    private void initComponents() {
        mapView = (MapView) findViewById(R.id.map_container);
        ImageView ivhome = (ImageView) this.findViewById(R.id.imageView_home);
        ivhome.setOnClickListener(new OnClickListener() {

            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                Intent intent = new Intent(Maps.this, GridViewContainer.class);
                startActivity(intent);
                finish();
            }
        });
    }

    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }

    class MapOverlay extends Overlay {

        private GeoPoint pointToDraw;

        public void setPointToDraw(GeoPoint point) {
            pointToDraw = point;
        }

        public GeoPoint getPointToDraw() {
            return pointToDraw;
        }

        @Override
        public boolean draw(Canvas canvas, MapView mapView, boolean shadow,
                long when) {
            super.draw(canvas, mapView, shadow);
            Point screenPts = new Point();
            mapView.getProjection().toPixels(pointToDraw, screenPts);
            Bitmap bmp = BitmapFactory.decodeResource(getResources(),
                R.drawable.select_map);
            canvas.drawBitmap(bmp, screenPts.x, screenPts.y - 24, null);
            return true;
        }
    }
}

main.xml:

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@android:color/black"
        android:orientation="vertical" >

        <com.google.android.maps.MapView
            android:id="@+id/map_container"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:apiKey="yor api key"
            android:clickable="true"
            android:focusable="true" />

    </LinearLayout>

並在清單中定義如下權限:

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

#4樓

public static Location getBestLocation(Context ctxt) {
    Location gpslocation = getLocationByProvider(
        LocationManager.GPS_PROVIDER, ctxt);
    Location networkLocation = getLocationByProvider(
        LocationManager.NETWORK_PROVIDER, ctxt);
    Location fetchedlocation = null;
    // if we have only one location available, the choice is easy
    if (gpslocation != null) {
        Log.i("New Location Receiver", "GPS Location available.");
        fetchedlocation = gpslocation;
    } else {
        Log.i("New Location Receiver",
            "No GPS Location available. Fetching Network location lat="
                + networkLocation.getLatitude() + " lon ="
                + networkLocation.getLongitude());
        fetchedlocation = networkLocation;
    }
    return fetchedlocation;
}

/**
 * get the last known location from a specific provider (network/gps)
 */
private static Location getLocationByProvider(String provider, Context ctxt) {
    Location location = null;
    // if (!isProviderSupported(provider)) {
    // return null;
    // }
    LocationManager locationManager = (LocationManager) ctxt
            .getSystemService(Context.LOCATION_SERVICE);
    try {
        if (locationManager.isProviderEnabled(provider)) {
            location = locationManager.getLastKnownLocation(provider);
        }
    } catch (IllegalArgumentException e) {
        Log.i("New Location Receiver", "Cannot access Provider " + provider);
    }
    return location;
}

#5樓

簡單而最佳的地理位置定位方法。

LocationManager lm = null;
boolean network_enabled;


if (lm == null)
                lm = (LocationManager) Kikit.this.getSystemService(Context.LOCATION_SERVICE);

            network_enabled = lm.isProviderEnabled(LocationManager.NETWORK_PROVIDER);

            dialog = ProgressDialog.show(Kikit.this, "", "Fetching location...", true);


            final Handler handler = new Handler();
            timer = new Timer();
            TimerTask doAsynchronousTask = new TimerTask() {

                @Override
                public void run() {
                    handler.post(new Runnable() {

                        @Override
                        public void run() 
                        {

                            Log.e("counter value","value "+counter);

                            if(counter<=8)
                            {
                                try 
                                {
                                    counter++;


                                    if (network_enabled) {

                                        lm = (LocationManager) Kikit.this.getSystemService(Context.LOCATION_SERVICE);

                                        Log.e("in network_enabled..","in network_enabled");

                                        // Define a listener that responds to location updates
                                        LocationListener locationListener = new LocationListener() 
                                        {


                                            public void onLocationChanged(Location location) 
                                            {
                                                if(attempt == false)

                                                {
                                                    attempt = true;
                                                    Log.e("in location listener..","in location listener..");
                                                    longi = location.getLongitude();
                                                    lati = location.getLatitude();
                                                    Data.longi = "" + longi; 
                                                    Data.lati = "" + lati;


                                                    Log.e("longitude : ",""+longi);
                                                    Log.e("latitude : ",""+lati);



                                                    if(faceboo_name.equals(""))
                                                    {
                                                        if(dialog!=null){
                                                        dialog.cancel();}
                                                        timer.cancel();
                                                        timer.purge();
                                                        Data.homepage_resume = true;
                                                        lm = null;
                                                        Intent intent = new Intent();                              
                                                        intent.setClass(Kikit.this,MainActivity.class);

                                                        startActivity(intent);      
                                                        finish();
                                                    }
                                                    else
                                                    {           

                                                        isInternetPresent = cd.isConnectingToInternet();

                                                        if (isInternetPresent) 
                                                        {
                                                            if(dialog!=null)
                                                                dialog.cancel();

                                                            Showdata();
                                                        }
                                                        else
                                                        {
                                                            error_view.setText(Data.internet_error_msg);
                                                            error_view.setVisibility(0);
                                                            error_gone();
                                                        }

                                                    }   
                                                }

                                            }

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

                                            public void onProviderEnabled(String provider) {
                                                //Toast.makeText(getApplicationContext(), "Location enabled", Toast.LENGTH_LONG).show();

                                            }

                                            public void onProviderDisabled(String provider) {


                                            }
                                        };



                                        // Register the listener with the Location Manager to receive
                                        // location updates
                                        lm.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 100000, 10,locationListener);

                                    } else{
                                        //Toast.makeText(getApplicationContext(), "No Internet Connection.", 2000).show();
                                        buildAlertMessageNoGps();

                                    }



                                } catch (Exception e) {
                                    // TODO
                                    // Auto-generated
                                    // catch
                                    // block
                                }
                            }
                            else
                            {

                                timer.purge();
                                timer.cancel();

                                if(attempt == false)
                                {
                                    attempt = true;

                                    String locationProvider = LocationManager.NETWORK_PROVIDER;
                                    // Or use LocationManager.GPS_PROVIDER

                                    try {
                                        Location lastKnownLocation = lm.getLastKnownLocation(locationProvider);

                                        longi = lastKnownLocation.getLongitude();
                                        lati = lastKnownLocation.getLatitude();
                                        Data.longi = "" + longi; 
                                        Data.lati = "" + lati;
                                    } catch (Exception e) {
                                        // TODO Auto-generated catch block
                                        e.printStackTrace();
                                        Log.i("exception in loc fetch", e.toString());
                                    }

                                    Log.e("longitude of last known location : ",""+longi);
                                    Log.e("latitude of last known location : ",""+lati);

                                    if(Data.fb_access_token == "")
                                    {

                                        if(dialog!=null){
                                            dialog.cancel();}
                                        timer.cancel();
                                        timer.purge();
                                        Data.homepage_resume = true;
                                        Intent intent = new Intent();                              
                                        intent.setClass(Kikit.this,MainActivity.class);

                                        startActivity(intent);  
                                        finish();
                                    }
                                    else
                                    {           

                                        isInternetPresent = cd.isConnectingToInternet();

                                        if (isInternetPresent) 
                                        {
                                            if(dialog!=null){
                                                dialog.cancel();}           
                                            Showdata();
                                        }
                                        else
                                        {
                                            error_view.setText(Data.internet_error_msg);
                                            error_view.setVisibility(0);
                                            error_gone();
                                        }

                                    }   

                                }
                            }
                        }
                    });
                }
            };
            timer.schedule(doAsynchronousTask, 0, 2000);


private void buildAlertMessageNoGps() {
        final AlertDialog.Builder builder = new AlertDialog.Builder(this);

        builder.setMessage("Your WiFi & mobile network location is disabled , do you want to enable it?")
        .setCancelable(false)
        .setPositiveButton("Yes", new DialogInterface.OnClickListener() {


            public void onClick(@SuppressWarnings("unused") final DialogInterface dialog, @SuppressWarnings("unused") final int id) 
            {
                startActivity(new Intent(android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS));
                setting_page = true;
            }
        })
        .setNegativeButton("No", new DialogInterface.OnClickListener() {
            public void onClick(final DialogInterface dialog, @SuppressWarnings("unused") final int id) {
                dialog.cancel();
                finish();
            }
        });
        final AlertDialog alert = builder.create();
        alert.show();
    }
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