<分区>
当我点击当前按钮获取用户的当前位置然后给出空指针异常即使我检查 fusedapi 是否被授予并且当用户允许当前位置访问时我检索当前位置但它显示错误
map fragment
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View rootview = inflater.inflate(R.layout.fragment_map, container, false);
latlng.add(new LatLng(22.32371, 73.16409));
latlng.add(new LatLng(22.32737, 73.17566));
latlng.add(new LatLng(22.28, 73.1903696));
latlng.add(new LatLng(22.334, 73.21853));
latlng.add(new LatLng(22.40303, 73.22369));
latlng.add(new LatLng(22.55148, 72.97035));
SupportMapFragment mapFragment = (SupportMapFragment) getChildFragmentManager().findFragmentById(R.id.map); //use SuppoprtMapFragment for using in fragment instead of activity MapFragment = activity SupportMapFragment = fragment
mapFragment.getMapAsync(this);
askPermission();
createGoogleApi();
mbtn = rootview.findViewById(R.id.myLocationButton);
mbtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
getcurrentmarker();
}
});
return rootview;
}
@Override
public void onMapReady(GoogleMap googleMap)
{
mgoogleMap = googleMap;
mgoogleMap.setOnMarkerClickListener(this);
}
@Override
public void onStart() {
super.onStart();
// Call GoogleApiClient connection when starting the Activity
googleApiClient.connect();
}
@Override
public void onStop() {
super.onStop();
// Disconnect GoogleApiClient when stopping Activity
googleApiClient.disconnect();
}
private void createGoogleApi()
{
Log.d(TAG, "createGoogleApi()");
if ( googleApiClient == null )
{
googleApiClient = new GoogleApiClient.Builder( getContext() )
.addConnectionCallbacks(this)
.addOnConnectionFailedListener( this )
.addApi(LocationServices.API)
.build();
}
}
// Check for permission to access Location
private boolean checkPermission() {
Log.d(TAG, "checkPermission()");
// Ask for permission if it wasn't granted yet
return (ContextCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED );
}
// Asks for permission
private void askPermission() {
Log.d(TAG, "askPermission()");
ActivityCompat.requestPermissions(
MapFragment.super.getActivity(),
new String[] { Manifest.permission.ACCESS_FINE_LOCATION },
REQ_PERMISSION
);
}
// Verify user's response of the permission requested
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if (requestCode == REQ_PERMISSION) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(getContext(), "Permission", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getContext(), "Permission DENIED", Toast.LENGTH_SHORT).show();
}
}
}
// App cannot work without the permissions
private void permissionsDenied() {
Log.w(TAG, "permissionsDenied()");
}
// Start location Updates
private void startLocationUpdates(){
Log.i(TAG, "startLocationUpdates()");
locationRequest = LocationRequest.create()
.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
.setInterval(6000)
.setFastestInterval(5000);
//movement in meter
if ( checkPermission() )
LocationServices.FusedLocationApi.requestLocationUpdates(googleApiClient, locationRequest, this);
}
@Override
public void onLocationChanged(Location location) {
Log.d(TAG, "onLocationChanged ["+location+"]");
lastLocation = location;
writeActualLocation(location);
}
@Override
public void onConnected(@Nullable Bundle bundle) {
Log.i(TAG, "onConnected()");
getLastKnownLocation();
}
// GoogleApiClient.ConnectionCallbacks suspended
@Override
public void onConnectionSuspended(int i) {
Log.w(TAG, "onConnectionSuspended()");
}
// GoogleApiClient.OnConnectionFailedListener fail
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
Log.w(TAG, "onConnectionFailed()");
}
// Get last known location
private void getLastKnownLocation() {
Log.d(TAG, "getLastKnownLocation()");
if ( checkPermission() ) {
lastLocation = LocationServices.FusedLocationApi.getLastLocation(googleApiClient);
if ( lastLocation != null ) {
Log.i(TAG, "LasKnown location. " +
"Long: " + lastLocation.getLongitude() +
" | Lat: " + lastLocation.getLatitude());
writeLastLocation();
startLocationUpdates();
} else {
Log.w(TAG, "No location retrieved yet");
startLocationUpdates();
}
}
else askPermission();
}
private void writeActualLocation(Location location)
{
lastLocation = location;
showmarker(latlng);
}
private void writeLastLocation() {
writeActualLocation(lastLocation);
}
private void getcurrentmarker()
{
if (ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getContext(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
mgoogleMap.setMyLocationEnabled(true);
mgoogleMap.getUiSettings().setMyLocationButtonEnabled(false);
mgoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(lastLocation.getLatitude(), lastLocation.getLongitude()), 14));
}
private void showmarker(List<LatLng> positions)
{
Log.d(TAG,"show");
if(!markers.equals(null))
{
markers.clear();
}
if ( marker != null ) {
marker.remove();
}
for (LatLng position : positions) {
Marker marker = mgoogleMap.addMarker(
new MarkerOptions()
.position(position)
.visible(false)); // Invisible for now
markers.add(marker);
}
for (Marker marker : markers) {
if (SphericalUtil.computeDistanceBetween(new LatLng(lastLocation.getLatitude(),lastLocation.getLongitude()), marker.getPosition()) < 400) {
marker.setVisible(true);
float zoom = 14f;
CameraUpdate cameraUpdate1 = CameraUpdateFactory.newLatLngZoom(marker.getPosition(), zoom);
mgoogleMap.animateCamera(cameraUpdate1);
}
}
}
@Override
public boolean onMarkerClick(Marker marker)
{
BottomSheetFragment bottomSheetFragment = new BottomSheetFragment(lastLocation,marker.getPosition());
bottomSheetFragment.show(getFragmentManager(), bottomSheetFragment.getTag());
return false;
}
}
list
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
在连接 googleapiclient 之前，我请求获得当前位置的许可，然后检索当前位置，然后单击当前位置按钮
日志
java.lang.NullPointerException: Attempt to invoke virtual method 'double android.location.Location.getLatitude()' on a null object reference
at com.example.eats.Fragment.MapFragment.getcurrentmarker(MapFragment.java:256)