我正在创建一个应用程序以显示地图并获取我的当前位置。我正在使用GPSTracker API。这是一项服务。我需要在GPSTracker获取当前位置时等待用户加载（进度条或其他类型的加载）。但是，如果我在调用getMapAsync（）和GPSTracker之前在MapFragment中打开一个对话框，则系统找不到该对话框，因为它不在当前线程中。我正在考虑使用广播，但我不知道该如何使用。
那是我的代码
MapFragment.java
public class MapFragment extends Fragment implements LocationListener {
private View rootView;
private GPSTracker gpsTracker;
private GoogleMap map;
double latitude;
double longitude;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.map, container, false);
setLocation();
return rootView;
}
public void setLocation() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
gpsTracker = new GPSTracker(getActivity(), true);
}
if (gpsTracker.canGetLocation()) {
latitude = gpsTracker.getLatitude();
longitude = gpsTracker.getLongitude();
setMap();
} else {
gpsTracker.showSettingsAlert();
}
}
public void setMap() {
MapView mapView = (MapView) rootView.findViewById(R.id.mapView);
mapView.onCreate(null);
mapView.onResume();
mapView.getMapAsync(
new OnMapReadyCallback() {
@Override
public void onMapReady(GoogleMap googlemap) {
map = googlemap;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
MapsInitializer.initialize(getContext());
}
map.setMapType(GoogleMap.MAP_TYPE_NORMAL);
if (ActivityCompat.checkSelfPermission(getActivity(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getActivity(), 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;
}
map.setMyLocationEnabled(true);
while (latitude == 0 && longitude == 0) {
gpsTracker.getLocation();
latitude = gpsTracker.getLatitude();
longitude = gpsTracker.getLongitude();
}
LatLng marker = new LatLng(latitude, longitude);
map.moveCamera(CameraUpdateFactory.newLatLngZoom(marker, Constants.CAMERA_ZOOM));
}
}
);
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
}
这就是服务
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
LocationManager mLocationManager;
// 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, boolean getLocation) {
this.mContext = context;
if (getLocation) {
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){
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
if(locationManager!=null){
location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if (location == null) {
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);
// location = getLastKnownLocation();
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.PASSIVE_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
if(locationManager!=null){
location = locationManager.getLastKnownLocation(LocationManager.PASSIVE_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
private Location getLastKnownLocation() {
mLocationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE);
List<String> providers = mLocationManager.getProviders(true);
Location bestLocation = null;
for (String provider : providers) {
if (ActivityCompat.checkSelfPermission(mContext, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(mContext, 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 bestLocation;
}
Location l = mLocationManager.getLastKnownLocation(provider);
if (l == null) {
continue;
}
if (bestLocation == null || l.getAccuracy() < bestLocation.getAccuracy()) {
// Found best last known location: %s", l);
bestLocation = l;
}
}
return bestLocation;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(GPSTracker.this);
}
}
/**
* 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);
alertDialog.setTitle("GPS desligado");
alertDialog.setMessage("Por favor, ligue o GPS do seu dispositivo!");
// On pressing Settings button
alertDialog.setPositiveButton("Ligar", 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("Cancelar", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
public void resetLocation() {
this.location = null;
}
@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;
}
}