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public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
MyItem myItem;
private ClusterManager<MyItem> mClusterManager;
@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 to 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) {
mMap = googleMap;
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(31.530136,74.353225), 10));
// Initialize the manager with the context and the map.
// (Activity extends context, so we can pass 'this' in the constructor.)
mClusterManager = new ClusterManager<MyItem>(this, mMap);
// Point the map's listeners at the listeners implemented by the cluster
// manager.
mMap.setOnCameraChangeListener(mClusterManager);
mMap.setOnMarkerClickListener(mClusterManager);
// Add cluster items (markers) to the cluster manager.
// addItems();
myItem = new MyItem(31.530136,74.353225);
mClusterManager.addItem(myItem);
myItem = new MyItem(31.529807, 74.352495);
mClusterManager.addItem(myItem);
myItem = new MyItem(31.530584, 74.353729);
mClusterManager.addItem(myItem);
myItem = new MyItem(31.531319, 74.351217);
mClusterManager.addItem(myItem);
// Add a marker in Sydney and move the camera
// LatLng sydney = new LatLng(-34, 151);
// mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
// mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
}
private void addItems() {
// Set some lat/lng coordinates to start with.
double lat = 31.531034;
double lng = 74.352374;
// Add ten cluster items in close proximity, for purposes of this example.
for (int i = 0; i < 10; i++) {
double offset = i/60d;
lat = lat + offset;
lng = lng + offset;
MyItem offsetItem = new MyItem(lat, lng);
mClusterManager.addItem(offsetItem);
}
}
}
Die obige Klasse stellt den Code zum Hinzufügen von Marker-Koordinaten in Cluster-Dienstprogramm-Bibliothek von Google Maps in Android angeboten. Aber wenn ich den Code ausführe gibt es den Fehler bei mClustermanager.addItem() gibt Nullzeiger Ausnahme.mClustermanager.additem() Google Maps werfen Nullzeiger Ausnahme android
es scheint, dass Ihre "mMap" ist Null –
Wenn ich einfach Marker mit mMap anwenden, funktioniert es tatsächlich, aber mit Clustermanager null Nullzeiger Ausnahme –
haben Sie ClusterItem für MyItem Klasse implementiert? –