我有一个扩展 LiveData 类的 LocationListener。从 Android 6.0 开始，权限是在运行时请求的。现在，当我尝试实现 LiveData 类时，它需要权限检查onActive()功能。我必须在每个活动中为请求的权限和收到的结果制作样板代码。 有什么方法可以将此类
onRequestPermissionsResult()和checkSelfPermission()功能移动到 LocationListener ？
LocationFragment.java
public class LocationFragment extends LifecycleFragment {
private FragmentLocationBinding binding;
public LocationFragment() {
// Required empty public constructor
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
if (ContextCompat.checkSelfPermission(getActivity(),
permission.ACCESS_COARSE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
// Should we show an explanation?
if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(),
Manifest.permission.ACCESS_COARSE_LOCATION)) {
// Show an explanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
} else {
// No explanation needed, we can request the permission.
ActivityCompat.requestPermissions(getActivity(),
new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
200);
// MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
// app-defined int constant. The callback method gets the
// result of the request.
}
}
//get the viewmodel from activity
LastLocationViewModel lastLocationViewModel = ViewModelProviders.of(getActivity())
.get(LastLocationViewModel.class);
lastLocationViewModel.getLastKnowLocation().observe(this, location -> {
binding.setLocation(location);
});
}
@Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case 200: {
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(getActivity(), "Rights Granted", Toast.LENGTH_SHORT).show();
// permission was granted, yay! Do the
// contacts-related task you need to do.
} else {
// permission denied, boo! Disable the
// functionality that depends on this permission.
}
return;
}
// other 'case' lines to check for other
// permissions this app might request
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
binding = DataBindingUtil
.inflate(LayoutInflater.from(getActivity()), R.layout.fragment_location, null, false);
return binding.getRoot();
}
}
LastLocationListener.java
public class LastLocationListener extends LiveData<Location> {
private LocationManager locationManager;
private Context context;
private LocationListener listener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
Log.d("Location Msg", location.toString());
setValue(location);
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
@Override
public void onProviderEnabled(String s) {
}
@Override
public void onProviderDisabled(String s) {
}
};
public LastLocationListener(Context context) {
this.context = context;
locationManager = (LocationManager) context.getSystemService(
Context.LOCATION_SERVICE);
}
@Override
protected void onActive() {
if (ActivityCompat.checkSelfPermission(context, permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED
&& ActivityCompat.checkSelfPermission(context, 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(LocationManager.NETWORK_PROVIDER, 0, 0, listener);
}
@Override
protected void onInactive() {
locationManager.removeUpdates(listener);
}
}