我的应用在访问MapActivity class时崩溃了。
该应用只有两个类，返回错误的类负责加载地图并允许用户选择喜欢的地方。
使用API 21运行项目不会出现错误，但是当我更改为使用API23运行项目时，应用程序在从一个活动切换到另一个活动时结束。
logcat错误
.MapsActivity}: java.lang.IllegalArgumentException: invalid provider: null
MapsActivity类
public class MapsActivity extends AppCompatActivity implements GoogleMap.OnMapLongClickListener, LocationListener {
private GoogleMap mMap;
int location = -1;
LocationManager locationManager;
String provider;
/**
* ATTENTION: This was auto-generated to implement the App Indexing API.
* See https://g.co/AppIndexing/AndroidStudio for more information.
*/
private GoogleApiClient client;
@Override
public void onMapLongClick(LatLng point) {
Geocoder geocoder = new Geocoder(getApplicationContext(), Locale.getDefault());
String label = new Date().toString();
try {
List<Address> listAddresses = geocoder.getFromLocation(point.latitude, point.longitude, 1);
if (listAddresses != null && listAddresses.size() > 0) {
label = listAddresses.get(0).getAddressLine(0);
}
} catch (IOException e) {
e.printStackTrace();
}
MainActivity.places.add(label);
MainActivity.arrayAdapter.notifyDataSetChanged();
MainActivity.locations.add(point);
mMap.addMarker(new MarkerOptions()
.position(point)
.title(label)
.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED)));
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
provider = locationManager.getBestProvider(new Criteria(), false);
ActionBar actionBar = getActionBar();
if (actionBar != null) {
actionBar.setDisplayHomeAsUpEnabled(true);
}
Intent i = getIntent();
location = i.getIntExtra("locationInfo", -1);
setUpMapIfNeeded();
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
}
@Override
protected void onResume() {
super.onResume();
setUpMapIfNeeded();
if (location == -1 || location == 0) {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
locationManager.requestLocationUpdates(provider, 400, 1, this);
}
}
@Override
protected void onPause() {
super.onPause();
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
locationManager.removeUpdates(this);
}
/**
* Sets up the map if it is possible to do so (i.e., the Google Play services APK is correctly
* installed) and the map has not already been instantiated.. This will ensure that we only ever
* call {@link #setUpMap()} once when {@link #mMap} is not null.
* <p/>
* If it isn't installed {@link SupportMapFragment} (and
* {@link MapView MapView}) will show a prompt for the user to
* install/update the Google Play services APK on their device.
* <p/>
* A user can return to this FragmentActivity after following the prompt and correctly
* installing/updating/enabling the Google Play services. Since the FragmentActivity may not
* have been completely destroyed during this process (it is likely that it would only be
* stopped or paused), {@link #onCreate(Bundle)} may not be called again so we should call this
* method in {@link #onResume()} to guarantee that it will be called.
*/
private void setUpMapIfNeeded() {
// Do a null check to confirm that we have not already instantiated the map.
if (mMap == null) {
// Try to obtain the map from the SupportMapFragment.
mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map))
.getMap();
mMap.setOnMapLongClickListener(this);
// Check if we were successful in obtaining the map.
if (mMap != null) {
setUpMap();
}
}
}
/**
* This is where we can add markers or lines, add listeners or move the camera. In this case, we
* just add a marker near Africa.
* <p/>
* This should only be called once and when we are sure that {@link #mMap} is not null.
*/
private void setUpMap() {
if (location != -1 && location != 0) {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
locationManager.removeUpdates(this);
mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(MainActivity.locations.get(location), 10));
mMap.addMarker(new MarkerOptions().position(MainActivity.locations.get(location)).title(MainActivity.places.get(location)));
} else {
locationManager.requestLocationUpdates(provider, 400, 1, this);
}
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return true;
}
locationManager.removeUpdates(this);
this.finish();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
@Override
public void onLocationChanged(Location userLocation) {
mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(userLocation.getLatitude(), userLocation.getLongitude()), 10));
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
public void onStart() {
super.onStart();
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
client.connect();
Action viewAction = Action.newAction(
Action.TYPE_VIEW, // TODO: choose an action type.
"Maps Page", // TODO: Define a title for the content shown.
// TODO: If you have web page content that matches this app activity's content,
// make sure this auto-generated web page URL is correct.
// Otherwise, set the URL to null.
Uri.parse("http://host/path"),
// TODO: Make sure this auto-generated app deep link URI is correct.
Uri.parse("android-app://luizugliano.com.br.lugaresfavoritos/http/host/path")
);
AppIndex.AppIndexApi.start(client, viewAction);
}
@Override
public void onStop() {
super.onStop();
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
Action viewAction = Action.newAction(
Action.TYPE_VIEW, // TODO: choose an action type.
"Maps Page", // TODO: Define a title for the content shown.
// TODO: If you have web page content that matches this app activity's content,
// make sure this auto-generated web page URL is correct.
// Otherwise, set the URL to null.
Uri.parse("http://host/path"),
// TODO: Make sure this auto-generated app deep link URI is correct.
Uri.parse("android-app://luizugliano.com.br.lugaresfavoritos/http/host/path")
);
AppIndex.AppIndexApi.end(client, viewAction);
client.disconnect();
}
}
答案 0 :(得分：2)
路易斯，
正如@Fabin Paul所提到的，用户需要允许应用程序的位置权限从API级别23开始运行。
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
// No explanation needed, we can request the permission.
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
MY_PERMISSIONS_REQUEST_FINE_LOCATION);
// MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
// app-defined int constant. The callback method gets the
// result of the request.
} else {
//Permission is granted
}
您还需要覆盖以下方法：
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_FINE_LOCATION: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
showAlert(getString(R.string.error), getString(R.string.message));
}
}
// other 'case' lines to check for other
// permissions this app might request
}
}
请查看此link