Fragment中onRequestPermissionsResult不触发问题求助

Hey there! Let's troubleshoot why your onRequestPermissionsResult isn't triggering after the user accepts location permissions in your PerdidosMapa_Fragment. Here are the most common fixes and checks to resolve this:

If you're using getActivity().requestPermissions(...) to ask for permissions, the result will be sent to the parent Activity's onRequestPermissionsResult instead of the Fragment's. Make sure you call the Fragment's own requestPermissions method:

// Correct way in Fragment
private static final int LOCATION_PERMISSION_CODE = 100;

// When you need to request permissions
requestPermissions(
    new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
    LOCATION_PERMISSION_CODE
);

If your parent Activity overrides onRequestPermissionsResult, you must call super.onRequestPermissionsResult(...)—otherwise, the Fragment will never receive the result. Here's how to fix that:

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    // Your Activity-specific logic (if any) goes here
}

Make sure the request code you use when calling requestPermissions matches the one you check in onRequestPermissionsResult. A typo here will cause the callback to ignore the result:

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (requestCode == LOCATION_PERMISSION_CODE) { // Use the SAME constant as the request
        if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
            // Permission granted, execute your logic
            Log.i("Permission", "Location access approved!");
        }
    }
}

The old onRequestPermissionsResult system is deprecated, and using the Activity Result Contracts is more reliable. It eliminates callback passing issues entirely. Here's how to implement it in your Fragment:

private ActivityResultLauncher<String> locationPermissionLauncher;

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // Register the permission launcher
    locationPermissionLauncher = registerForActivityResult(
        new ActivityResultContracts.RequestPermission(),
        isGranted -> {
            if (isGranted) {
                // Permission accepted, do your work
                Log.i("Permission", "Location permission granted!");
            } else {
                // Permission denied, handle accordingly
                Log.i("Permission", "Location permission denied.");
            }
        }
    );
}

// Call this method to request permission
private void askForLocationPermission() {
    locationPermissionLauncher.launch(Manifest.permission.ACCESS_FINE_LOCATION);
}

If the user has already granted the permission, the request dialog won't pop up, so the callback won't trigger. Always verify the permission status before requesting:

if (ContextCompat.checkSelfPermission(requireContext(), Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
    // Permission already exists, skip request and run your logic
    return;
}
// Only request permission if it's not granted
requestPermissions(...);

If none of these fixes work, feel free to share the full code for how you're requesting permissions and your complete onRequestPermissionsResult method—we can dig deeper!

内容的提问来源于stack exchange，提问作者Budha 600