Question

我有这种问题：我在Fragment中的应用程序中使用GoogleMaps地图，并且在调用onLocationChanged方法时会中断。问题是这条线

mMap.moveCamera（CameraUpdatesFactory.newLatLngZoom（position，15）;

可能是因为找不到mMap或我不知道。这是代码部分：

public class home extends AppCompatActivity implements OnMapReadyCallback, GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener{

GoogleMap mMap;
Marker marker;

private void checkAndStartLocationUpdate() {
    if (permissionGranted && googleApiClientReady) {
        Log.d("MainActivity", "Start updating location");
        LocationRequest mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(10000);
        mLocationRequest.setFastestInterval(5000);
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        try {

            LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);

            lm = (LocationManager)getSystemService(Context.LOCATION_SERVICE);

            SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
            mapFragment.getMapAsync(this);

            location = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);

        } catch (SecurityException e) {
            e.printStackTrace();
        }
    }
}

public void onLocationChanged(Location location) {

    Log.d("MainActivity", "Location update received: " + location.toString());

    latitude = location.getLatitude();
    longitude = location.getLongitude();

    Log.d("MainActivity", longitude + " " + latitude);

    LatLng position = new LatLng(longitude, latitude);
    marker.setPosition(position);
    mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(position, 15));

}

Answer 1

您可以选择

@Override
public void onMapReady(GoogleMap googleMap)
{
    mMap = googleMap;

    // Tika
    // Tika
    // Tika
}

并更改

mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(position, 15));

到

if(mMap != null)
   mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(position, 15));

或者您可以简单地致电

    LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);

在onMapReady之后的mMap = googleMap;内部

onLocationChanged（）中的map.moveCamera

1 个答案: