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。

其他回答

在过去一年多的时间里,我使用GPS_PROVIDER和NETWORK_PROVIDER的组合来获取当前位置,它运行得很好,但从过去几个月开始,我在经过长时间的延迟后才获取位置,所以我改用了最新的API FusedLocationProviderClient,它运行的很好。

下面是我使用FusedLocationProviderClient编写的获取当前位置的类。在下面的代码中,我使用了一个计时器等待一段时间以获取当前位置,我安排了计时器15秒的延迟,您可以根据您的情况进行更改。

private static FusedLocationService ourInstance;
private final LocationRequest locationRequest;
private FusedLocationProviderClient mFusedLocationClient;
private Location mLastLocation;
private Context context;
private FindOutLocation findOutLocation;
private boolean callbackTriggered = false;
private Timer timer;

public static FusedLocationService getInstance(Context pContext) {

    if (null == ourInstance) ourInstance = new FusedLocationService(pContext);

    return ourInstance;
}

private FusedLocationService(Context pContext) {
    context = pContext;
    mFusedLocationClient = LocationServices.getFusedLocationProviderClient(context);
    locationRequest = getLocationRequest();
    requestLocation(context);
}

public Location getLastKnownLocation() {
    return mLastLocation;
}

private void requestLocation(Context context) {

    if (ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        return;
    }
    mFusedLocationClient.requestLocationUpdates(locationRequest, mLocationCallback, null);
    mFusedLocationClient.getLastLocation().addOnSuccessListener(location -> {
        if (location != null) {
            mLastLocation = location;
            triggerCallback(mLastLocation);
        }
    });
}

private LocationRequest getLocationRequest() {
    LocationRequest locationRequest = new LocationRequest();
    long INTERVAL = 10 * 1000;
    long FASTEST_INTERVAL = 5 * 1000;
    locationRequest.setInterval(INTERVAL);
    locationRequest.setFastestInterval(FASTEST_INTERVAL);
    locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    return locationRequest;
}

private LocationCallback mLocationCallback = new LocationCallback() {
    @Override
    public void onLocationResult(LocationResult locationResult) {
        for (Location location : locationResult.getLocations()) {
            if (location != null) mLastLocation = location;
        }
        if (null != mLastLocation) triggerCallback(mLastLocation);
    }
};

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

@SuppressLint("MissingPermission")
public void findLocation(FindOutLocation findOutLocation) {
    long TIMER_TIME_OUT = 15 * 1000;
    this.findOutLocation = findOutLocation;
    callbackTriggered = false;

    try {
        requestLocation(context);
        timer = new Timer();
        timer.schedule(new GetLastLocation(context), TIMER_TIME_OUT);
    } catch (Exception e) {
        e.printStackTrace();
    }
}

private class GetLastLocation extends TimerTask {
    Context context;

    GetLastLocation(Context context) {
        this.context = context;
    }

    @Override
    public void run() {
        triggerCallback(mLastLocation);
    }
}

private void triggerCallback(Location location) {
    if (null != location) mLastLocation = location;
    if (!callbackTriggered && null != findOutLocation) {
        callbackTriggered = true;
        removeLocationUpdates();
        findOutLocation.gotLocation(location);
        findOutLocation = null;
    }
}

private void removeLocationUpdates() {
    if (null != timer) timer.cancel();
    if (null != mFusedLocationClient)
        mFusedLocationClient.removeLocationUpdates(mLocationCallback);
}
}

这是从活动中调用的,下面是代码

    FusedLocationService.FindOutLocation findOutLocation = new FusedLocationService.FindOutLocation() {
        @Override
        public void gotLocation(Location currentLocation) {
            if (currentLocation != null) {
                /*TODO DO SOMETHING WITH CURRENT LOCATION*/
            }
        }
    };
    FusedLocationService.getInstance(this).findLocation(findOutLocation);

在AndroidManifest.xml中添加以下条目

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

<!-- Needed only if your app targets Android 5.0 (API level 21) or higher. -->
<uses-feature android:name="android.hardware.location.gps" />

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。

Kotlin版本的@Fedor Greate回答:

类的用法:

val locationResult = object : MyLocation.LocationResult() {

    override fun gotLocation(location: Location?) {

        val lat = location!!.latitude
        val lon = location.longitude

        Toast.makeText(context, "$lat --SLocRes-- $lon", Toast.LENGTH_SHORT).show()
    }

}

val myLocation = MyLocation()
myLocation.getLocation(inflater.context, locationResult)

MyLocation类:

class MyLocation {
    internal lateinit var timer1: Timer
    internal var lm: LocationManager? = null
    internal lateinit var locationResult: LocationResult
    internal var gps_enabled = false
    internal var network_enabled = false

    internal var locationListenerGps: LocationListener = object : LocationListener {


        override fun onLocationChanged(location: Location) {
            timer1.cancel()
            locationResult.gotLocation(location)
            lm!!.removeUpdates(this)
            lm!!.removeUpdates(locationListenerNetwork)
        }

        override fun onProviderDisabled(provider: String) {}
        override fun onProviderEnabled(provider: String) {}
        override fun onStatusChanged(provider: String, status: Int, extras: Bundle) {}
    }

    internal var locationListenerNetwork: LocationListener = object : LocationListener {
        override fun onLocationChanged(location: Location) {
            timer1.cancel()
            locationResult.gotLocation(location)
            lm!!.removeUpdates(this)
            lm!!.removeUpdates(locationListenerGps)
        }

        override fun onProviderDisabled(provider: String) {}
        override fun onProviderEnabled(provider: String) {}
        override fun onStatusChanged(provider: String, status: Int, extras: Bundle) {}
    }

    fun getLocation(context: Context, result: LocationResult): Boolean {
        //I use LocationResult callback class to pass location value from MyLocation to user code.
        locationResult = result
        if (lm == null)
            lm = context.getSystemService(Context.LOCATION_SERVICE) as LocationManager?

        //exceptions will be thrown if provider is not permitted.
        try {
            gps_enabled = lm!!.isProviderEnabled(LocationManager.GPS_PROVIDER)
        } catch (ex: Exception) {
        }

        try {
            network_enabled = lm!!.isProviderEnabled(LocationManager.NETWORK_PROVIDER)
        } catch (ex: Exception) {
        }

        //don't start listeners if no provider is enabled
        if (!gps_enabled && !network_enabled)
            return false

        if (ActivityCompat.checkSelfPermission(context,
                Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED ||
            ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) run {

            ActivityCompat.requestPermissions(context as Activity,
                arrayOf(Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION), 111)
        }


        if (gps_enabled)
            lm!!.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0f, locationListenerGps)
        if (network_enabled)
            lm!!.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0f, locationListenerNetwork)
        timer1 = Timer()
        timer1.schedule(GetLastLocation(context), 20000)
        return true
    }

    internal inner class GetLastLocation(var context: Context) : TimerTask() {
        override fun run() {
            lm!!.removeUpdates(locationListenerGps)
            lm!!.removeUpdates(locationListenerNetwork)

            var net_loc: Location? = null
            var gps_loc: Location? = null

            if (ActivityCompat.checkSelfPermission(context,
                    Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED ||
                ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED
            ) run {

                ActivityCompat.requestPermissions(context as Activity,
                    arrayOf(Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION),111)
            }


            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)
        }
    }

     abstract class LocationResult {
          abstract fun gotLocation(location: Location?)
    }
}

对@Fedor解决方案的改进。我们可以使用位置管理器的requestSingleUpdate方法,而不是使用“0”时间间隔和“0”距离请求位置。更新的代码(kotlin版本)

import android.annotation.SuppressLint
import android.content.Context
import android.location.Criteria
import android.location.Location
import android.location.LocationListener
import android.location.LocationManager
import android.os.Bundle
import java.util.*

@SuppressLint("MissingPermission")
class AppLocationProvider {

  private lateinit var timer: Timer
  private var locationManager: LocationManager? = null
  private lateinit var locationCallBack: LocationCallBack
  private var gpsEnabled = false
  private var networkEnabled = false

  private var locationListener: LocationListener = object : LocationListener {

    override fun onLocationChanged(location: Location) {
      timer.cancel()
      locationCallBack.locationResult(location)
    }

    override fun onProviderDisabled(provider: String) {}
    override fun onProviderEnabled(provider: String) {}
    override fun onStatusChanged(provider: String, status: Int, extras: Bundle) {}
  }

  fun getLocation(context : Context, callBack: LocationCallBack): Boolean {
    locationCallBack = callBack
    if (locationManager == null)
      locationManager = context.getSystemService(Context.LOCATION_SERVICE) as LocationManager?

    //exceptions will be thrown if provider is not permitted.
    try {
      gpsEnabled = locationManager!!.isProviderEnabled(LocationManager.GPS_PROVIDER)
    } catch (ex: Exception) {
      ex.printStackTrace()
    }

    try {
      networkEnabled = locationManager!!.isProviderEnabled(LocationManager.NETWORK_PROVIDER)
    } catch (ex: Exception) {
      ex.printStackTrace()
    }

    //don't start listeners if no provider is enabled
    if (!gpsEnabled && !networkEnabled)
      return false

    val criteria = Criteria()
    if (gpsEnabled) {
      criteria.accuracy = Criteria.ACCURACY_FINE
    } else {
      criteria.accuracy = Criteria.ACCURACY_COARSE
    }
    locationManager!!.requestSingleUpdate(criteria, locationListener, null)

    timer = Timer()
    timer.schedule(GetLastKnownLocation(), 5000)
    return true
  }

  inner class GetLastKnownLocation : TimerTask() {

    override fun run() {
      locationManager!!.removeUpdates(locationListener)

      var netLoc: Location? = null
      var gpsLoc: Location? = null

      if (gpsEnabled)
        gpsLoc = locationManager!!.getLastKnownLocation(LocationManager.GPS_PROVIDER)
      if (networkEnabled)
        netLoc = locationManager!!.getLastKnownLocation(LocationManager.NETWORK_PROVIDER)

      //check which value use the latest one
      if (gpsLoc != null && netLoc != null) {
        if (gpsLoc.time > netLoc.time)
          locationCallBack.locationResult(gpsLoc)
        else
          locationCallBack.locationResult(netLoc)
        return
      }

      if (gpsLoc != null) {
        locationCallBack.locationResult(gpsLoc)
        return
      }
      if (netLoc != null) {
        locationCallBack.locationResult(netLoc)
        return
      }
      locationCallBack.locationResult(null)
    }
  }

  interface LocationCallBack {
    fun locationResult(location: Location?)
  }
}

要获取位置,只需调用getLocation方法-

AppLocationProvider().getLocation(context, object : AppLocationProvider.LocationCallBack {
  override fun locationResult(location: Location?) {
    // use location, this might get called in a different thread if a location is a last known location. In that case, you can post location on main thread
  }
})

注:在调用getLocation方法之前,必须授予所需的位置权限。

看到所有答案后,提出问题(最简单、最稳健)。我只点击了图书馆Android ReactiveLocation。

当我制作一个位置跟踪应用程序时。然后我意识到,通过优化电池处理位置跟踪是非常典型的。

所以我想告诉新手和开发者,他们不想在未来的优化中维护他们的位置代码。使用此库。

ReactiveLocationProvider locationProvider = new 

    ReactiveLocationProvider(context);
    locationProvider.getLastKnownLocation()
        .subscribe(new Consumer<Location>() {
            @Override
            public void call(Location location) {
                doSthImportantWithObtainedLocation(location);
            }
        });

要放入应用程序级别build.gradle的依赖项

dependencies {
    ...
    compile 'pl.charmas.android:android-reactive-location2:2.1@aar'
    compile 'com.google.android.gms:play-services-location:11.0.4' //you can use newer GMS version if you need
    compile 'com.google.android.gms:play-services-places:11.0.4'
    compile 'io.reactivex:rxjava:2.0.5' //you can override RxJava version if you need
}

使用此库的优点:

现在和将来都将积极维护这种自由。您不必担心电池优化。因为开发人员已经尽力了。易于安装,放置依赖项和播放。轻松连接到Play Services API获取最后一个已知位置订阅位置更新使用位置设置API管理地理围栏地址列表的地理编码位置活动识别使用当前位置API获取位置自动完成建议