问题
I have an Activity that implements Google Maps.When I start it, the activity stops for a few seconds, until the Map is completely loaded. I would like to use a ProgressDialog until the map does not load, but I can not start it in a background thread, since the map must be loaded in the main thread, as explained in this link.
How can I make it without using the AsyncTask?
Otherwise, is there a way to start the activity immediately and show the not loaded map with the gray background as does the Google Maps application?
That's the code of the onCreate method:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_mappa);
databaseHelper = new MyDatabaseHelper(this);
Bundle b = getIntent().getExtras();
String placeAddress= "";
if(b != null)
placeAddress= b.getString("indirizzo");
setUpMapIfNeeded();
gMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
gMap.setMyLocationEnabled(true);
UiSettings settings = gMap.getUiSettings();
settings.setMyLocationButtonEnabled(true);
LocationManager locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
String provider = locationManager.getBestProvider(criteria, false);
Location location = locationManager.getLastKnownLocation(provider);
double lat = location.getLatitude();
double lng = location.getLongitude();
position = new LatLng(lat, lng);
if(!placeAddress.equals("")){
Geocoder geocoder = new Geocoder(this, Locale.getDefault());
List<Address> indirizzi = null;
try {
indirizzi = geocoder.getFromLocationName(placeAddress, 1);
} catch (IOException e) {
e.printStackTrace();
}
double latLuogo = indirizzi.get(0).getLatitude();
double lngLuogo = indirizzi.get(0).getLongitude();
LatLng luogo = new LatLng(latLuogo, lngLuogo);
CameraPosition cameraPosition = new CameraPosition.Builder()
.target(luogo)
.zoom(15)
.build();
gMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
}
else{
CameraPosition cameraPosition = new CameraPosition.Builder()
.target(position)
.zoom(15)
.build();
gMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
}
LocationListener listener = new LocationListener() {
public void onLocationChanged(Location location){
//makeUseOfNewLocation(location);
}
@Override
public void onProviderDisabled(String arg0) {}
@Override
public void onProviderEnabled(String arg0) {}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
locationManager.requestLocationUpdates(provider, 0, 10, listener);
ConnectivityManager connMngr = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
final NetworkInfo netInfo = connMngr.getActiveNetworkInfo();
if(checkConnection(netInfo) == true ){
loadFromDatabase(); //load markers
gMap.setInfoWindowAdapter(new InfoWindowAdapter(){
@Override
public View getInfoWindow(Marker marker) {
return null;
}
@Override
public View getInfoContents(Marker marker) {
String nome = marker.getTitle();
String indirizzo = marker.getSnippet();
View v = getLayoutInflater().inflate(R.layout.info_window_layout, null);
TextView title = (TextView)v.findViewById(R.id.titleInfoWindow);
title.setText(nome);
TextView snippet = (TextView)v.findViewById(R.id.snippetInfoWindow);
snippet.setText(indirizzo);
ImageView imView = (ImageView)v.findViewById(R.id.info_windowImageView);
impostaImmagine(imView, nome);
return v;
}
});
gMap.setOnInfoWindowClickListener(new GoogleMap.OnInfoWindowClickListener() {
@Override
public void onInfoWindowClick(Marker marker) {
final String nome = marker.getTitle();
final String indirizzo = marker.getSnippet();
startLuogoActivity(nome, indirizzo);
}
});
final Geocoder geocoder = new Geocoder(this, Locale.getDefault());
gMap.setOnMapLongClickListener(new GoogleMap.OnMapLongClickListener() {
@Override
public void onMapLongClick(LatLng point) {
List<Address> addresses = null;
if(checkConnection(netInfo) == true){
try {
addresses = geocoder.getFromLocation(point.latitude, point.longitude, 1);
} catch (IOException e) {
e.printStackTrace();
}
if(addresses!=null){
String address = addresses.get(0).getAddressLine(0);
String city = addresses.get(0).getAddressLine(1);
String country = addresses.get(0).getAddressLine(2);
String indirizzo = address + ", " + city + ", " + country;
final Dialog addByClickDialog = onCreateDialogADDByClick(getBaseContext(), indirizzo);
addByClickDialog.show();
Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
v.vibrate(50);
}else{
final Dialog nessunaConnessioneDialog = onCreateDialogNessunaConnessione(getBaseContext());
nessunaConnessioneDialog.show();
Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
v.vibrate(50);
}
}
else{
final Dialog nessunaConnessioneDialog = onCreateDialogNessunaConnessione(getBaseContext());
nessunaConnessioneDialog.show();
Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
v.vibrate(50);
}
}
});
Button addButton = (Button)findViewById(R.id.addButton);
final Dialog addDialog;
if(checkConnection(netInfo) == false){
addDialog = onCreateDialogADD(getBaseContext(), false);
}else{
addDialog = onCreateDialogADD(getBaseContext(), true);
}
addButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
addDialog.show();
}
});
Button deleteButton = (Button)findViewById(R.id.deleteButton);
final Dialog deleteDialog;
if(checkConnection(netInfo) == false){
deleteDialog = onCreateDialogDELETE(getBaseContext(), false);
}else{
deleteDialog = onCreateDialogDELETE(getBaseContext(), true);
}
deleteButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
deleteDialog.show();
}
});
}
回答1:
Check the answer by @commonsware on ProgressDialog not shown in UIThread question. It might not be a good idea to use ProgressDialog for a MapActivity because time it takes to display a MapView is mostly dependent upon the Internet connection back to the Google Maps servers. You have no way to know when the MapView is done loading, so you have no way to know when to dismiss the dialog. But still if you are very sure that it will always load and will take less time, then you can read more here. You may also want to see the relate question which points to same link: Android : showDialog when setContentView loading
Hope this helps.
回答2:
I finally solved the problem!I used the code present in this tutorial.
All I had to do is to load the map and the markers in the point of this code where is present the "setContentView(R.layout.main);" call.
回答3:
Follow below Steps:
1)Implements GoogleMap.OnMapLoadedCallback.
Callback interface for when the map is ready to be used.
2)ProgressDialog code inside onCreate Method.
//show Progress
3)onMapReady method
@Override
public void onMapReady(GoogleMap googleMap) {
Log.d(TAG, "OnMapReady");
mMap = googleMap;
mMap.setOnMapLoadedCallback(this);
3)onMapLoaded() call when maps loads.
public void onMapLoaded() {
// hide progress
}
Please check point 3 it is important.
来源：https://stackoverflow.com/questions/16952830/android-progressdialog-while-loading-google-maps