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
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" />
其他回答
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：）
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
这是我请求用户权限的方式。
在AndroidManifest.xml中的应用程序标记外添加这些权限请求。
<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" />
然后在App Gradle文件中添加Google的位置依赖项。
implementation 'com.google.android.gms:play-services-location:15.0.0'
现在声明一些全局变量。
private lateinit var mFusedLocationProvider:FusedLocationProviderClient
private lateinit var mLocationCallback: LocationCallback
private lateinit var mLocationRequest: LocationRequest
private var mLocationPermissionGranted:Boolean = false
在活动的OnCreate方法中（我无法正确格式化代码，对此深表歉意）
mFusedLocationProvider = LocationServices.getFusedLocationProviderClient(this)
//Location Callback
mLocationCallback = object: LocationCallback(){
override fun onLocationResult(p0: LocationResult?) {
if(p0==null){
//todo(request user to enable location from settings then remove return)
return
}else{
getDeviceLocation()
}
}
}
//Location Request
mLocationRequest = LocationRequest.create()
mLocationRequest.priority = LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY
//Set the Interval for Latest Interval Update
mLocationRequest.interval = 5000
//Set How Many Location Updated you Want
mLocationRequest.numUpdates = 1
getLocationPermission()
getDeviceLocation()
现在创建这两个函数。
private fun getLocationPermission() {
val permission:Array<String> = arrayOf(android.Manifest.permission.ACCESS_FINE_LOCATION,android.Manifest.permission.ACCESS_COARSE_LOCATION)
if(ContextCompat.checkSelfPermission(applicationContext,Constant.FINE_LOCATION)== PermissionChecker.PERMISSION_GRANTED){
if(ContextCompat.checkSelfPermission(applicationContext,Constant.COARSE_LOCATION)== PermissionChecker.PERMISSION_GRANTED){
mLocationPermissionGranted = true
}
}else{
ActivityCompat.requestPermissions(this,permission,Constant.LOCATION_REQUEST_CODE)
}
}
第二种方法
private fun getDeviceLocation() {
try{
if(mLocationPermissionGranted){
mFusedLocationProvider.lastLocation.addOnCompleteListener(this,{task: Task<Location> ->
if(task.isSuccessful){
var currentLocation: Location? = task.result
if(currentLocation!=null){
Log.i("Location","Latitude is ${currentLocation.latitude} and Longitude" +
"${currentLocation.longitude}")
}
else
mFusedLocationProvider.requestLocationUpdates(mLocationRequest,mLocationCallback,null)
}
})
}
}catch (e:SecurityException){
Log.e("Error", "Security Exception ${e.message}")
}
}
对于常量.kt
class Constant{
companion object {
//Location Request Settings
const val SET_INTERVAL:Long = 2000
const val NUM_UPDATES:Int = 1
//Location Permission
const val FINE_LOCATION:String = android.Manifest.permission.ACCESS_FINE_LOCATION
const val COARSE_LOCATION:String = android.Manifest.permission.ACCESS_COARSE_LOCATION
}
}
你可以一直使用LocationManager.getLastKnownLocation（），但就像它说的那样，它可能已经过时了。
获取一般位置的一个简单方法是注册网络（通常很快）。
LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, 1000, 1000, this);
然后做
locationManager.removeUpdates(this);
在侦听器的onLocationChanged（）方法中。
在android系统中获取位置更新需要很多东西，需要大量的bolierplate代码。
你需要照顾好
Google Play服务可用性检查，更新Google play服务，如果它是旧的或不可用GoogleApiClient的对话框创建及其连接、断开等回调。停止并释放用于位置更新的资源处理位置权限方案检查位置服务是否打开或关闭获取最新位置也不是那么容易如果在一定时间后未找到位置，则回退到最后一个已知位置
我已经创建了Android EasyLocation（小型Android库），它将处理所有这些事情，您可以专注于业务逻辑。
您只需要扩展EasyLocationActivity
requestSingleLocationFix(easyLocationRequest);
or
requestLocationUpdates(easyLocationRequest);
点击此处查看示例应用程序和所需步骤https://github.com/akhgupta/Android-EasyLocation
