我使用以下代码来获取当前位置的lat和lang，但它在CameraPosition中给出了null值...任何想法为什么？
private void moveMapToMyLocation() {
LocationManager locMan = (LocationManager) MapsActivity.this.getSystemService(Context.LOCATION_SERVICE);
Criteria crit = new Criteria();
Location loc = locMan.getLastKnownLocation(LocationManager.GPS_PROVIDER);
CameraPosition camPos = new CameraPosition.Builder()
.target(new LatLng(loc.getLatitude(), loc.getLongitude()))
.zoom(12.8f)
.build();
CameraUpdate camUpdate = CameraUpdateFactory.newCameraPosition(camPos);
mMap.moveCamera(camUpdate);
}
答案 0 :(得分：1)
这是帮助类，它管理与GPS相关的操作。
if (v == rb2)
Toast.makeText(getApplicationContext(), rb2.getText().toString(), Toast.LENGTH_SHORT).show();
成功创建GPSTracker课程后，您需要在想要获取纬度和经度的活动中调用它。在onCreate方法中使用以下代码行。
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 1; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;
public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}
public Location getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(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
} else {
this.canGetLocation = true;
// First get location from Network Provider
if (isNetworkEnabled) {
try
{
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
}
catch (SecurityException e)
{
}
Log.d("Network", "Network");
if (locationManager != null) {
try
{
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
}
catch (SecurityException e)
{
}
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if (location == null) {
try
{
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
catch (SecurityException s)
{
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS(){
if(locationManager != null){
try
{
locationManager.removeUpdates(GPSTracker.this);
}
catch (SecurityException e)
{
}
}
}
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
* @return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS Settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not active. Do you want to open?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public IBinder onBind(Intent arg0) {
return null;
}
}
我们走到了尽头。请确保已授予所有权限
GPSTracker gps;
double latitude;
double longitude;
gps = new GPSTracker(getActivity());
// check if GPS enabled
if(gps.canGetLocation())
{
latitude = gps.getLatitude();
longitude = gps.getLongitude();
}
else
{
gps.showSettingsAlert();
}
答案 1 :(得分：0)
使用以下代码获取经度和纬度
LocationManager locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 2000, 10, locationListener);
myLocation = locationManager.getLastKnownLocation(LocationManager.PASSIVE_PROVIDER);
double longitude = myLocation.getLongitude();
double latitude = myLocation.getLatitude();
private final LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
longitude = location.getLongitude();
latitude = location.getLatitude();
}
}
答案 2 :(得分：0)
使用此方法，这将在您的情况下正常工作
private void initMap() {
try {
// Loading map
initilizeMap();
// Changing map type
googleMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
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;
}
googleMap.setMyLocationEnabled(true);
googleMap.getUiSettings().setZoomControlsEnabled(false);
googleMap.getUiSettings().setMyLocationButtonEnabled(true);
googleMap.getUiSettings().setCompassEnabled(true);
googleMap.getUiSettings().setRotateGesturesEnabled(true);
googleMap.getUiSettings().setZoomGesturesEnabled(true);
if (locationManager == null) {
locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
}
if (locationManager.getAllProviders().contains(LocationManager.GPS_PROVIDER)) {
isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
isNetworkProviderEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (isGPSEnabled) {
location = getLastLocationByProvider(locationManager, LocationManager.GPS_PROVIDER, getApplicationContext());
} else if (isNetworkProviderEnabled) {
location = getLastLocationByProvider(locationManager, LocationManager.NETWORK_PROVIDER, getApplicationContext());
}
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
} else {
if (isNetworkProviderEnabled) {
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 100000, 1, this);
provider_info = LocationManager.NETWORK_PROVIDER;
} else if (isGPSEnabled) {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 100000, 1, this);
provider_info = LocationManager.GPS_PROVIDER;
} else {
alertDialog = Util.showOkDialog(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (Env.currentActivity != null) {
if (Env.currentActivity instanceof LocationActivity) {
try {
gotoSettings();
} catch (Exception e) {
e.printStackTrace();
}
}
}
if (alertDialog != null) {
alertDialog.dismiss();
alertDialog = null;
}
}
}, this.getResources().getString(R.string.location_service_validation));
}
location = locationManager.getLastKnownLocation(provider_info);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
MarkerOptions marker = new MarkerOptions().position(
new LatLng(latitude, longitude))
.title(getFullAddressLine(this));
marker.icon(BitmapDescriptorFactory
.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
googleMap.addMarker(marker);
CameraPosition cameraPosition = new CameraPosition.Builder()
.target(new LatLng(latitude,
longitude)).zoom(15).build();
googleMap.animateCamera(CameraUpdateFactory
.newCameraPosition(cameraPosition));
}
} catch (Exception e) {
e.printStackTrace();
}
}
答案 3 :(得分：0)
尝试这可能这应该适合你。
LocationManager locationManager = (LocationManager) getActivity().getSystemService(getActivity().LOCATION_SERVICE);
Location loc = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (loc != null) {
onLocationChanged(loc);
} else {
loc = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (loc != null)
onLocationChanged(loc);
}
onLocationChanged。为此，您必须实现LocationListener（接口）。 一旦实现了LocationListener，就会得到一个名为onLocationChanged的覆盖方法。 通过这种方法，您将获得纬度和经度。
@Override
public void onLocationChanged(Location location) {
double dLatitude = location.getLatitude();
double dLongitude = location.getLongitude();
LatLng currentLatLng = new LatLng(dLatitude, dLongitude);
}