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
这里有点晚了，但在这种情况下，我会使用谷歌地图API，并使用谷歌地图的纬度和经度API标记附近的位置。另外，如果你能在地图上显示他/她的位置，用户体验会更好。无需担心用户位置的更新或使用android api搜索。让谷歌地图为您处理内部内容。
@emmby可能已经在他的应用程序中解决了这个问题，但为了将来的参考，我向其他开发人员推荐的是查看谷歌地图API中的位置特定内容。
编辑：在谷歌地图中显示用户位置的链接
其他回答
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);
}
}
});
}
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：）
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) {}
}
使用以下代码，它将提供可用的最佳提供商：
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);
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" />
