public class ThumbnailFragment extends Fragment { private static final int MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE = 1000; private List<ImageGroup> imageGroupList; private RecyclerView recyclerViewImages; private ThumbnailPageAdapter adapter; private RecyclerView.LayoutManager layoutManager; public ThumbnailFragment() { // Required empty public constructor } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fragment_thumbnail, container, false); layoutManager = new LinearLayoutManager(getContext()); adapter = new ThumbnailPageAdapter(); recyclerViewImages = (RecyclerView) view.findViewById(R.id.recyclerViewImages); recyclerViewImages.setLayoutManager(layoutManager); recyclerViewImages.setAdapter(adapter); // Here, thisActivity is the current activity if (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) { // Should we show an explanation? if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(), Manifest.permission.READ_EXTERNAL_STORAGE)) { // 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. // if we are in activity /* ActivityCompat.requestPermissions(getActivity(), new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);*/ // if we are in fragment requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE); // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an // app-defined int constant. The callback method gets the // result of the request. } } else { // if we have permission we can run our permission related task ListFiles(); } return view; } @Override public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) { switch (requestCode) { case MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE: { // If request is cancelled, the result arrays are empty. if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { // permission was granted, yay! Do the // permission-related task you need to do. // this will run just after granting permission // not always getActivity().runOnUiThread(new Runnable() { @Override public void run() { ListFiles(); } }); } 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 } } public void ListFiles() { final Path path = new Path(); final Search search = new Search(); final AddFileHelper addFileHelper = new AddFileHelper(adapter); search.setOnListFilesListener(new Search.OnListFilesListener() { @Override public void onNewFileFound(File file) { addFileHelper.addNewFile(file); } @Override public void onListCompleted(List<File> result) { //addFileHelper.close(); } }); Thread thread = new Thread(new Runnable() { @Override public void run() { search.listFiles(path.getDCIMFile()); } }); thread.start(); } }
References
https://developer.android.com/training/permissions/requesting.html