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
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);
}
}
});
}
其他回答
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);
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。
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
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?)
}
}
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。
