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public class MainActivity extends AppCompatActivity {
static ArrayList<String>places;
static ArrayList<String>lat;
static ArrayList<String>lng;
static ArrayAdapter arrayAdapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView listView = (ListView)findViewById(R.id.listView);
lat = new ArrayList<String>();
lng = new ArrayList<String>();
SharedPreferences sharedPreference = this.getSharedPreferences("com.example.inbal.memorableplaces", Context.MODE_PRIVATE);
try {
places =(ArrayList<String>) ObjectSerializer.deserialize(sharedPreference.getString("Places",ObjectSerializer.serialize(new ArrayList<String>())));
lat =(ArrayList<String>) ObjectSerializer.deserialize(sharedPreference.getString("Lat",ObjectSerializer.serialize(new ArrayList<String>())));
lng =(ArrayList<String>) ObjectSerializer.deserialize(sharedPreference.getString("Lng",ObjectSerializer.serialize(new ArrayList<String>())));
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
if (lat.size()==0)
lat.add("");
if (lng.size()==0)
lng.add("");
if (places.size()==0)
places.add("Add a new place");
arrayAdapter= new ArrayAdapter(this,android.R.layout.simple_list_item_1,places);
listView.setAdapter(arrayAdapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
Intent intent = new Intent(getApplicationContext(), MapsActivity.class);
intent.putExtra("placeName", i);
startActivity(intent);
}
});
}
}
public class MapsActivity extends FragmentActivity implements
OnMapReadyCallback,GoogleMap.OnMapLongClickListener{
private GoogleMap mMap;
LocationManager locationManager;
LocationListener locationListener;
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (grantResults.length>0&&grantResults[0]==PackageManager.PERMISSION_GRANTED){
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)== PackageManager.PERMISSION_GRANTED)
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,1,10,locationListener);
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready Gto be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
@Override
public void onMapReady(GoogleMap googleMap) {
Intent intent = getIntent();
int num = intent.getIntExtra("placeName", 0);
if (num == 0) {
mMap = googleMap;
mMap.setOnMapLongClickListener(this);
locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
locationListener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
LatLng userLocation = new LatLng(location.getLatitude(), location.getLongitude());
mMap.clear();
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(userLocation, 15));
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
@Override
public void onProviderEnabled(String s) {
}
@Override
public void onProviderDisabled(String s) {
}
};
if (Build.VERSION.SDK_INT < 23)
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1, 10, locationListener);
else {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED)
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 20, 10, locationListener);
else
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 1);
}
}
else {
String lat = MainActivity.lat.get(num);
String lng = MainActivity.lng.get(num);
LatLng location= new LatLng(Double.parseDouble(lat),Double.parseDouble(lng));
mMap.moveCamera(CameraUpdateFactory.newLatLng(location));
}
}
@Override
public void onMapLongClick(LatLng latLng)
{
Geocoder geocoder = new Geocoder(getApplicationContext(), Locale.getDefault());
try {
List<Address> listAddress = geocoder.getFromLocation(latLng.latitude,latLng.longitude,1);
String address = "";
if (listAddress!=null && listAddress.size()>0) {
if (listAddress.get(0).getLocality() != null) {
address+=listAddress.get(0).getLocality();
if (listAddress.get(0).getThoroughfare() != null)
address=address+", "+listAddress.get(0).getThoroughfare();
if (listAddress.get(0).getSubThoroughfare() != null)
address=address +" "+listAddress.get(0).getSubThoroughfare();
}
mMap.clear();
mMap.addMarker(new MarkerOptions().position(latLng).title(address));
}
MainActivity.places.add(address);
MainActivity.lat.add(Double.toString(latLng.latitude));
MainActivity.lng.add(Double.toString(latLng.longitude));
SharedPreferences sharedPreferences = this.getSharedPreferences("com.example.inbal.memorableplaces",Context.MODE_PRIVATE);
sharedPreferences.edit().putString("Places",ObjectSerializer.serialize(MainActivity.places)).apply();
sharedPreferences.edit().putString("Lat",ObjectSerializer.serialize(MainActivity.lat)).apply();
sharedPreferences.edit().putString("Lng",ObjectSerializer.serialize(MainActivity.lng)).apply();
MainActivity.arrayAdapter.notifyDataSetChanged();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Hey, ich baue ein Projekt, das Orte speichern sollte. Das einzige Problem ist, dass ich, nachdem ich vor Ort gedrückt und ihn gerettet habe, den Standort nicht mehr anzeigen kann. die Linie mMap.moveCamera(CameraUpdateFactory.newLatLng(location)); machen die App zum Absturz zu bringen, weil esKann verschieben Karte von LatLng
java.lang.NullPointerException sagt: Der Versuch, virtuelle Methode ‚Leere com.google.android.gms.maps.GoogleMap.moveCamera (com.google aufzurufen. android.gms.maps.CameraUpdate)‘ auf einer null-Objekt Referenz