[英]Android Google Maps API - cannot resolve “location.setLatitude()”
我正在尝试创建位置并设置纬度和经度,但是当我写
location.setLatitude
我越来越
无法解析符号
错误。 有人可以帮忙吗?
Location location = new Location("");
location.setLatitude(0.0d);
如果我这样更改代码:
Location location = new Location("")
.setLatitude(0.0d)
我出错了
不兼容的类型。 ; 必需:android.location.Location; 发现:无效
编辑:这是课程。 这实际上是Google教程中的代码。 我删除了一些不必要的部分,并添加了一些我需要的部分。
public class MapsActivity extends AppCompatActivity
implements OnMapReadyCallback {
private static final String TAG = MapsActivity.class.getSimpleName();
private GoogleMap mMap;
private CameraPosition mCameraPosition;
// The entry points to the Places API.
private GeoDataClient mGeoDataClient;
private PlaceDetectionClient mPlaceDetectionClient;
// The entry point to the Fused Location Provider.
private FusedLocationProviderClient mFusedLocationProviderClient;
// A default location (Sydney, Australia) and default zoom to use when location permission is
// not granted.
private final LatLng mDefaultLocation = new LatLng(49.656639, 19.636917);
private static final int DEFAULT_ZOOM = 15;
private static final int PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION = 1;
private boolean mLocationPermissionGranted;
// The geographical location where the device is currently located. That is, the last-known
// location retrieved by the Fused Location Provider.
private Location mLastKnownLocation;
// Keys for storing activity state.
private static final String KEY_CAMERA_POSITION = "camera_position";
private static final String KEY_LOCATION = "location";
// Used for selecting the current place.
private static final int M_MAX_ENTRIES = 5;
private String[] mLikelyPlaceNames;
private String[] mLikelyPlaceAddresses;
private String[] mLikelyPlaceAttributions;
private LatLng[] mLikelyPlaceLatLngs;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Retrieve location and camera position from saved instance state.
if (savedInstanceState != null) {
mLastKnownLocation = savedInstanceState.getParcelable(KEY_LOCATION);
mCameraPosition = savedInstanceState.getParcelable(KEY_CAMERA_POSITION);
}
// Retrieve the content view that renders the map.
setContentView(R.layout.activity_maps);
// Construct a GeoDataClient.
mGeoDataClient = Places.getGeoDataClient(this, null);
// Construct a PlaceDetectionClient.
mPlaceDetectionClient = Places.getPlaceDetectionClient(this, null);
// Construct a FusedLocationProviderClient.
mFusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this);
// Build the map.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
/**
* Saves the state of the map when the activity is paused.
*/
@Override
protected void onSaveInstanceState(Bundle outState) {
if (mMap != null) {
outState.putParcelable(KEY_CAMERA_POSITION, mMap.getCameraPosition());
outState.putParcelable(KEY_LOCATION, mLastKnownLocation);
super.onSaveInstanceState(outState);
}
}
LatLng centPoint = new LatLng(49.656639, 19.636917);
int kolStrefa = Color.argb(40, 255, 0, 0);
Location location = new Location("");
location.setLatitude(0.0d); //Cannot resolve symbol
@Override
public void onMapReady(GoogleMap map) {
mMap = map;
mMap.setMapType(GoogleMap.MAP_TYPE_HYBRID);
// Use a custom info window adapter to handle multiple lines of text in the
// info window contents.
// Prompt the user for permission.
getLocationPermission();
// Turn on the My Location layer and the related control on the map.
updateLocationUI();
// Get the current location of the device and set the position of the map.
getDeviceLocation();
CircleOptions strefa = new CircleOptions()
.center(centPoint)
.radius(200)
.strokeColor(Color.RED)
.fillColor(kolStrefa);
Circle circle = mMap.addCircle(strefa);
}
double distance = mLastKnownLocation.distanceTo(krzCent);
/**
* Gets the current location of the device, and positions the map's camera.
*/
private void getDeviceLocation() {
/*
* Get the best and most recent location of the device, which may be null in rare
* cases when a location is not available.
*/
try {
if (mLocationPermissionGranted) {
Task<Location> locationResult = mFusedLocationProviderClient.getLastLocation();
locationResult.addOnCompleteListener(this, new OnCompleteListener<Location>() {
@Override
public void onComplete(@NonNull Task<Location> task) {
if (task.isSuccessful()) {
// Set the map's camera position to the current location of the device.
mLastKnownLocation = task.getResult();
} else {
Log.d(TAG, "Current location is null. Using defaults.");
Log.e(TAG, "Exception: %s", task.getException());
mMap.moveCamera(CameraUpdateFactory
.newLatLngZoom(mDefaultLocation, DEFAULT_ZOOM));
mMap.getUiSettings().setMyLocationButtonEnabled(false);
}
}
});
}
} catch (SecurityException e) {
Log.e("Exception: %s", e.getMessage());
}
}
/**
* Prompts the user for permission to use the device location.
*/
private void getLocationPermission() {
/*
* Request location permission, so that we can get the location of the
* device. The result of the permission request is handled by a callback,
* onRequestPermissionsResult.
*/
if (ContextCompat.checkSelfPermission(this.getApplicationContext(),
android.Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
mLocationPermissionGranted = true;
} else {
ActivityCompat.requestPermissions(this,
new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION},
PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION);
}
}
/**
* Handles the result of the request for location permissions.
*/
@Override
public void onRequestPermissionsResult(int requestCode,
@NonNull String permissions[],
@NonNull int[] grantResults) {
mLocationPermissionGranted = false;
switch (requestCode) {
case PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
mLocationPermissionGranted = true;
}
}
}
updateLocationUI();
}
/**
* Prompts the user to select the current place from a list of likely places, and shows the
* current place on the map - provided the user has granted location permission.
*/
private void showCurrentPlace() {
if (mMap == null) {
return;
}
if (mLocationPermissionGranted) {
// Get the likely places - that is, the businesses and other points of interest that
// are the best match for the device's current location.
@SuppressWarnings("MissingPermission") final
Task<PlaceLikelihoodBufferResponse> placeResult =
mPlaceDetectionClient.getCurrentPlace(null);
placeResult.addOnCompleteListener
(new OnCompleteListener<PlaceLikelihoodBufferResponse>() {
@Override
public void onComplete(@NonNull Task<PlaceLikelihoodBufferResponse> task) {
if (task.isSuccessful() && task.getResult() != null) {
PlaceLikelihoodBufferResponse likelyPlaces = task.getResult();
// Set the count, handling cases where less than 5 entries are returned.
int count;
if (likelyPlaces.getCount() < M_MAX_ENTRIES) {
count = likelyPlaces.getCount();
} else {
count = M_MAX_ENTRIES;
}
int i = 0;
mLikelyPlaceNames = new String[count];
mLikelyPlaceAddresses = new String[count];
mLikelyPlaceAttributions = new String[count];
mLikelyPlaceLatLngs = new LatLng[count];
for (PlaceLikelihood placeLikelihood : likelyPlaces) {
// Build a list of likely places to show the user.
mLikelyPlaceNames[i] = (String) placeLikelihood.getPlace().getName();
mLikelyPlaceAddresses[i] = (String) placeLikelihood.getPlace()
.getAddress();
mLikelyPlaceAttributions[i] = (String) placeLikelihood.getPlace()
.getAttributions();
mLikelyPlaceLatLngs[i] = placeLikelihood.getPlace().getLatLng();
i++;
if (i > (count - 1)) {
break;
}
}
// Release the place likelihood buffer, to avoid memory leaks.
likelyPlaces.release();
// Show a dialog offering the user the list of likely places, and add a
// marker at the selected place.
openPlacesDialog();
} else {
Log.e(TAG, "Exception: %s", task.getException());
}
}
});
} else {
// The user has not granted permission.
Log.i(TAG, "The user did not grant location permission.");
// Add a default marker, because the user hasn't selected a place.
mMap.addMarker(new MarkerOptions()
.title("DEF")
.position(mDefaultLocation)
.snippet("DEFfd"));
// Prompt the user for permission.
getLocationPermission();
}
}
/**
* Displays a form allowing the user to select a place from a list of likely places.
*/
private void openPlacesDialog() {
// Ask the user to choose the place where they are now.
DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// The "which" argument contains the position of the selected item.
LatLng markerLatLng = mLikelyPlaceLatLngs[which];
String markerSnippet = mLikelyPlaceAddresses[which];
if (mLikelyPlaceAttributions[which] != null) {
markerSnippet = markerSnippet + "\n" + mLikelyPlaceAttributions[which];
}
// Add a marker for the selected place, with an info window
// showing information about that place.
mMap.addMarker(new MarkerOptions()
.title(mLikelyPlaceNames[which])
.position(markerLatLng)
.snippet(markerSnippet));
// Position the map's camera at the location of the marker.
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(markerLatLng,
DEFAULT_ZOOM));
}
};
// Display the dialog.
}
/**
* Updates the map's UI settings based on whether the user has granted location permission.
*/
private void updateLocationUI() {
if (mMap == null) {
return;
}
try {
if (mLocationPermissionGranted) {
mMap.setMyLocationEnabled(true);
mMap.getUiSettings().setMyLocationButtonEnabled(true);
} else {
mMap.setMyLocationEnabled(false);
mMap.getUiSettings().setMyLocationButtonEnabled(false);
mLastKnownLocation = null;
getLocationPermission();
}
} catch (SecurityException e) {
Log.e("Exception: %s", e.getMessage());
}
}
}
首先,您应该尝试创建一个全新的类并在此处创建此Location,以查看错误是否在其余代码中。
最后, Location location = new Location("").setLatitude(0.0d);
将不起作用,因为您首先创建位置,然后立即设置纬度。 Java认为您想将#setLatitude
的返回值分配给变量(由于返回void,因此这是不可能的)。
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