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

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/

其他回答

要获取并显示用户的当前位置,还可以使用MyLocationOverlay。假设您的活动中有一个mapView字段。要显示用户位置,只需执行以下操作:

myLocationOverlay = new MyLocationOverlay(this, mapView);
myLocationOverlay.enableMyLocation();
mapView.getOverlays().add(myLocationOverlay);

这将从GPS或网络获取当前位置。如果两者都失败,enableMyLocation()将返回false。

至于该区域周围事物的位置,ItemizedOverlay应该可以做到这一点。

我希望我没有误解你的问题。祝你好运

我已经在demonuts.com上写了详细的教程,介绍了当前位置。您可以在这里找到更多描述,也可以下载整个演示源代码以更好地理解。

这里已经有很多答案,但我想展示使用Google API获取位置的最新方法,这样新程序员就可以使用新方法:

首先,将其放在gradle文件中

compile 'com.google.android.gms:play-services:8.4.0'

然后实现必要的接口

public class MainActivity  extends BaseActivitiy implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, com.google.android.gms.location.LocationListener

声明实例

  private GoogleApiClient mGoogleApiClient;
  private Location mLocation;
  private LocationManager locationManager;
  private LocationRequest mLocationRequest;

将其放入onCreate()中

 mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

最后,重写必要的方法

 @Override
    public void onConnected(Bundle bundle) {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        mLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
        if(mLocation == null){
            startLocationUpdates();
        }
        if (mLocation != null) {
            double latitude = mLocation.getLatitude();
            double longitude = mLocation.getLongitude();
        } else {
            // Toast.makeText(this, "Location not Detected", Toast.LENGTH_SHORT).show();
        }
    }

    protected void startLocationUpdates() {
        // Create the location request
        mLocationRequest = LocationRequest.create()
                .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
                .setInterval(UPDATE_INTERVAL)
                .setFastestInterval(FASTEST_INTERVAL);
        // Request location updates
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient,
                mLocationRequest, this);
        Log.d("reque", "--->>>>");
    }

    @Override
    public void onConnectionSuspended(int i) {
        Log.i(TAG, "Connection Suspended");
        mGoogleApiClient.connect();
    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        Log.i(TAG, "Connection failed. Error: " + connectionResult.getErrorCode());
    }

    @Override
    public void onStart() {
        super.onStart();
        mGoogleApiClient.connect();
    }

    @Override
    public void onStop() {
        super.onStop();
        if (mGoogleApiClient.isConnected()) {
            mGoogleApiClient.disconnect();
        }
    }
    @Override
    public void onLocationChanged(Location location) {

    }

在运行应用程序之前,不要忘记在设备中启动GPS。

最近进行了重构以获得代码的位置,学习了一些好的想法,最终实现了一个相对完善的库和演示。

//request all valid provider(network/gps)
private boolean requestAllProviderUpdates() {
    checkRuntimeEnvironment();
    checkPermission();

    if (isRequesting) {
        EasyLog.d("Request location update is busy");
        return false;
    }


    long minTime = getCheckTimeInterval();
    float minDistance = getCheckMinDistance();

    if (mMapLocationListeners == null) {
        mMapLocationListeners = new HashMap<>();
    }

    mValidProviders = getValidProviders();
    if (mValidProviders == null || mValidProviders.isEmpty()) {
        throw new IllegalArgumentException("Not available provider.");
    }

    for (String provider : mValidProviders) {
        LocationListener locationListener = new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                if (location == null) {
                    EasyLog.e("LocationListener callback location is null.");
                    return;
                }
                printf(location);
                mLastProviderTimestamp = location.getTime();

                if (location.getProvider().equals(LocationManager.GPS_PROVIDER)) {
                    finishResult(location);
                } else {
                    doLocationResult(location);
                }

                removeProvider(location.getProvider());
                if (isEmptyValidProviders()) {
                    requestTimeoutMsgInit();
                    removeUpdates();
                }
            }

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

            @Override
            public void onProviderEnabled(String provider) {
            }

            @Override
            public void onProviderDisabled(String provider) {
            }
        };
        getLocationManager().requestLocationUpdates(provider, minTime, minDistance, locationListener);
        mMapLocationListeners.put(provider, locationListener);
        EasyLog.d("Location request %s provider update.", provider);
    }
    isRequesting = true;
    return true;
}

//remove request update
public void removeUpdates() {
    checkRuntimeEnvironment();

    LocationManager locationManager = getLocationManager();
    if (mMapLocationListeners != null) {
        Set<String> keys = mMapLocationListeners.keySet();
        for (String key : keys) {
            LocationListener locationListener = mMapLocationListeners.get(key);
            if (locationListener != null) {
                locationManager.removeUpdates(locationListener);
                EasyLog.d("Remove location update, provider is " + key);
            }
        }
        mMapLocationListeners.clear();
        isRequesting = false;
    }
}

//Compared with the last successful position, to determine whether you need to filter
private boolean isNeedFilter(Location location) {
    checkLocation(location);

    if (mLastLocation != null) {
        float distance = location.distanceTo(mLastLocation);
        if (distance < getCheckMinDistance()) {
            return true;
        }
        if (location.getAccuracy() >= mLastLocation.getAccuracy()
                && distance < location.getAccuracy()) {
            return true;
        }
        if (location.getTime() <= mLastProviderTimestamp) {
            return true;
        }
    }
    return false;
}

private void doLocationResult(Location location) {
    checkLocation(location);

    if (isNeedFilter(location)) {
        EasyLog.d("location need to filtered out, timestamp is " + location.getTime());
        finishResult(mLastLocation);
    } else {
        finishResult(location);
    }
}

//Return to the finished position
private void finishResult(Location location) {
    checkLocation(location);

    double latitude = location.getLatitude();
    double longitude = location.getLongitude();
    float accuracy = location.getAccuracy();
    long time = location.getTime();
    String provider = location.getProvider();

    if (mLocationResultListeners != null && !mLocationResultListeners.isEmpty()) {
        String format = "Location result:<%f, %f> Accuracy:%f Time:%d Provider:%s";
        EasyLog.i(String.format(format, latitude, longitude, accuracy, time, provider));

        mLastLocation = location;
        synchronized (this) {
            Iterator<LocationResultListener> iterator =  mLocationResultListeners.iterator();
            while (iterator.hasNext()) {
                LocationResultListener listener = iterator.next();
                if (listener != null) {
                    listener.onResult(location);
                }
                iterator.remove();
            }
        }
    }
}

完整代码:https://github.com/bingerz/FastLocation/blob/master/fastlocationlib/src/main/java/cn/bingerz/fastlocation/FastLocation.java

*每次请求完成位置时,最好删除更新,否则手机状态栏将始终显示定位图标。

我不确定基于位置的服务是否可以从GPS以外的其他基础设施获取位置,但根据那篇文章,这似乎是可能的:

应用程序可以调用几种类型的定位方法。使用移动电话网络:当前单元格ID可用于识别基站收发信机(BTS)设备正在通信以及该BTS的位置。显然,这种方法的准确性取决于单元格的大小,以及可能非常不准确。GSM蜂窝可以是2到20直径千米。另外与细胞ID一起使用的技术可以精度在150米以内。使用卫星:全球定位系统(GPS),受控美国国防部使用由24颗卫星组成的星座围绕地球运行。GPS确定通过计算设备的位置时间差信号来自不同的卫星到达接受者GPS信号是编码的,所以移动设备必须配备使用GPS接收器。GPS是可能是最准确的方法(如果GPS接收机具有清晰的天空视图),但它也有一些缺点:硬件可能很昂贵电池使用时,需要冷启动后的热身对可见卫星的初步定位。它还受到“峡谷效应”的影响在城市,卫星能见度是间歇性的。使用短程定位信标:相对小面积,如单个建筑,局域网可以提供其他位置服务。例如,适当地配备的设备可以使用蓝牙短程定位。

地理定位的简单和最佳方式。

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();
    }