Fragment implementa AbslistView.InetemClickListener Aener Con ArrayAdapter==> OnItemClick Listener è nullo

Question

La mia implementazione di un ABSListView.InetemClickListener in un frammento non esegue alcuna azione e visualizza alcun errore, quando una voce di elenco viene toccato.

Leggo la documentazione, ho cercato Google & Sof e leggi la sorgente SDK, ma non ha potuto risolvere il problema.

L'attività:

public class VenueActivity extends Activity implements
        NBVenuesFragment.OnFragmentInteractionListener,
        NBFriendsFragment.OnFragmentInteractionListener,
        UploadedPhotosFragment.OnFragmentInteractionListener {

    private static final String TAB_KEY_INDEX = "tab_key";
    private static final String TAG = "VenueActivity";
    private Fragment mCurrentFragment = null;
    private Fragment mNewFragment = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);

        setContentView(R.layout.activity_venue);

        ActionBar actionbar = getActionBar();
        actionbar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        ActionBar.Tab mVenuesFragmentTab = actionbar.newTab().setText(
                 getString(R.string.ui_nearby_venues_tab));
        ActionBar.Tab mNBFriendsFragmentTab = actionbar.newTab().setText(
                 getString(R.string.ui_nearby_friends_tab));
        ActionBar.Tab mUploadedPhotosFragmentTab = actionbar.newTab().setText("Photos Uploaded");

        Fragment mVenuesFragment = new NBVenuesFragment();
        Fragment mNBFriendsFragment = new NBFriendsFragment();
        Fragment mUploadedPhotosFragment = new UploadedPhotosFragment();

        mVenuesFragmentTab.setTabListener(new VenueTabsListener(mVenuesFragment,
                getApplicationContext()));

        mNBFriendsFragmentTab.setTabListener(new VenueTabsListener(mNBFriendsFragment,
                getApplicationContext()));

        mUploadedPhotosFragmentTab.setTabListener(new VenueTabsListener(mUploadedPhotosFragment,
                getApplicationContext()));

        actionbar.addTab(mVenuesFragmentTab);
        //actionbar.addTab(mNBFriendsFragmentTab);
        actionbar.addTab(mUploadedPhotosFragmentTab);

        if (savedInstanceState != null) {
            actionbar.setSelectedNavigationItem(savedInstanceState.getInt(
                    TAB_KEY_INDEX, 0));
        }

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu items for use in the action bar
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.venue_activity_actions, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.action_check_in:
                Toast.makeText(this, getString(R.string.action_check_in),
                        Toast.LENGTH_SHORT).show();
                return true;
            case android.R.id.home:
                // app icon in action bar clicked; goto parent activity.
                this.onBackPressed();
                return true;
        }
        return false;
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt(TAB_KEY_INDEX, getActionBar()
                .getSelectedNavigationIndex());

    }

    @Override
    public void onNearByVenueSelection(VenuesDummyData.VenuesDummyItem venueData){

        Bundle args = new Bundle();

        args.putString("VENUE_ID", venueData.venueId);
        args.putString("VENUE_NAME", venueData.venueName);
        args.putString("VENUE_ADDRESS", venueData.venueAddress);
        args.putString("VENUE_CHECK_INS", venueData.venueCheckIns);
        args.putString("VENUE_LIKES", venueData.venueLikes);
        args.putString("VENUE_CHECK_INS_FLIRT", venueData.venueCheckInsflirt);
        args.putString("VENUE_CHECK_INS_FRIENDS", venueData.venueCheckInsFriends);
        args.putString("OMEGA", venueData.omega);

        Fragment mVenueDetailsFragment = new VenueDetailsFragment();
        mVenueDetailsFragment.setArguments(args);

        mCurrentFragment = new NBVenuesFragment();
        mNewFragment = mVenueDetailsFragment;

        FragmentManager mFragmentManager = getFragmentManager();
        String tag = mVenueDetailsFragment.getTag();

        FragmentTransaction ft = mFragmentManager.beginTransaction();
        ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
        ft.replace(R.id.fragment_container, mVenueDetailsFragment, tag);
        ft.commit();

    }

    @Override
    public void onNearByFriendSelection(JsonObject mUserInfo){

        Bundle args = new Bundle();
        args.putString("FRIEND_NAME", mUserInfo.get("name").getAsString());
        //args.putString("FRIEND_ID", mUserInfo.friendId);
        args.putString("FRIEND_PHOTO", mUserInfo.get("photo_url").getAsString());
        //args.putString("VENUE_ID", mUserInfo.venueId);
        //args.putString("VENUE_NAME", mUserInfo.venueName);
        Fragment mFriendDetailsFragment = new FriendDetailsFragment();
        mFriendDetailsFragment.setArguments(args);

        mCurrentFragment = new NBFriendsFragment();
        mNewFragment = mFriendDetailsFragment;

        FragmentManager mFragmentManager = getFragmentManager();
        String tag = mFriendDetailsFragment.getTag();

        FragmentTransaction ft = mFragmentManager.beginTransaction();
        ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
        ft.replace(R.id.fragment_container, mFriendDetailsFragment, tag);
        //ft.addToBackStack(tag);
        ft.commit();

    }

    @Override
    public void onUserSelection(JsonObject mUserInfo){

        Log.i(TAG, "onUserSelection");
        Log.i(TAG, "mUserInfo ==> " + mUserInfo.toString());

        Bundle args = new Bundle();
        args.putString("USER_NAME", mUserInfo.get("name").getAsString());
        //args.putString("FRIEND_ID", mUserInfo.friendId);
        args.putString("USER_PHOTO", mUserInfo.get("photo_url").getAsString());
        //args.putString("VENUE_ID", mUserInfo.venueId);
        //args.putString("VENUE_NAME", mUserInfo.venueName);

        Fragment mUserDetailsFragment = new UserDetailsFragment();
        mUserDetailsFragment.setArguments(args);

        mCurrentFragment = new UploadedPhotosFragment();
        mNewFragment = mUserDetailsFragment;

        FragmentManager mFragmentManager = getFragmentManager();
        String tag = mUserDetailsFragment.getTag();

        FragmentTransaction ft = mFragmentManager.beginTransaction();
        ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
        ft.replace(R.id.fragment_container, mUserDetailsFragment, tag);
        //ft.addToBackStack(tag);
        ft.commit();

    }

    @Override
    public void onBackPressed() {
        if (mCurrentFragment != null && mNewFragment != null) {

            String tag = mCurrentFragment.getTag();

            FragmentManager mFragmentManager = getFragmentManager();
            FragmentTransaction ft = mFragmentManager.beginTransaction();
            ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
            ft.remove(mNewFragment);
            ft.replace(R.id.fragment_container, mCurrentFragment, tag);
            ft.commit();

            mCurrentFragment = null;
            mNewFragment = null;
        } else {
            super.onBackPressed();
        }
    }

}

class VenueTabsListener implements ActionBar.TabListener {
    public Fragment fragment;
    public Context context;

    public VenueTabsListener(Fragment fragment, Context context) {
        this.fragment = fragment;
        this.context = context;

    }

    @Override
    public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {
        //Toast.makeText(context, "Reselected!", Toast.LENGTH_SHORT).show();

    }

    @Override
    public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {
        //Toast.makeText(context, "Selected!", Toast.LENGTH_SHORT).show();
        ft.replace(R.id.fragment_container, fragment);
    }

    @Override
    public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) {
        //Toast.makeText(context, "Unselected!", Toast.LENGTH_SHORT).show();
        ft.remove(fragment);
    }

}

.

Il frammento dell'elenco:

public class UploadedPhotosFragment extends Fragment implements AbsListView.OnItemClickListener {

    private OnFragmentInteractionListener mListener;
    private AbsListView mListView;
    private JsonObject mUserInfo;
    private PhotosAdapter mAdapter;
    private JsonArray mDataFromServer;
    private String TAG = "UploadedPhotosFragment";



    private void getPhotosData() {
        Log.i(TAG, "getPhotosData");

        AsyncTask<Void, Void, FlefuApiMessagesGetPhotosResponseMessage> photosJsonString;
        photosJsonString = new GetPhotos() {

            @Override
            protected void onPostExecute(FlefuApiMessagesGetPhotosResponseMessage response) {

                Log.i(TAG, "@overridden GetPhotos onPostExecute: " + response.getData());
                mDataFromServer = (JsonArray)new JsonParser().parse(response.getData());
                mUserInfo = new JsonObject();

                for (int i = 0; i < mDataFromServer.size(); i++) {
                    mUserInfo = mDataFromServer.get(i).getAsJsonObject();
                    mAdapter.add(mUserInfo);
                }

            }
        };

        photosJsonString.execute();
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        getPhotosData();
        mAdapter = new PhotosAdapter(getActivity());
        Log.i(TAG, "onCreate");
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        Log.i(TAG, "onCreateView");

        View view = inflater.inflate(R.layout.fragment_photo_image, container, false);

        //int cols = getResources().getDisplayMetrics().widthPixels / getResources().getDisplayMetrics().densityDpi;
        mListView = (AbsListView) view.findViewById(R.id.photos);
        //mListView.setNumColumns(3);
        mListView.setAdapter(mAdapter);

        mListView.setOnItemClickListener(this);

        return view;
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        try {
            mListener = (OnFragmentInteractionListener) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString()
                    + " must implement OnFragmentInteractionListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    private class PhotosAdapter extends ArrayAdapter <JsonObject> {
        private LayoutInflater inflater;

        private class ViewHolder {
            TextView name;
            //TextView venue;
            ImageView thumb;
        }

        public PhotosAdapter(Context context) {
            super(context, R.layout.uploaded_image);

            Log.i(TAG, context.toString());

            inflater = LayoutInflater.from(context);
            Log.i(TAG, "PhotosAdapter");
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            Log.i(TAG, "getView");


            ViewHolder holder;

            if(convertView == null) {
                holder = new ViewHolder();
                convertView = inflater.inflate(R.layout.uploaded_image, null);
                holder.name = (TextView) convertView.findViewById(R.id.name);
                holder.thumb = (ImageView) convertView.findViewById(R.id.image);
                //holder.venueName = (TextView) convertView.findViewById(R.id.venueName);
                convertView.setTag(holder);
            } else {
                holder = (ViewHolder) convertView.getTag();
            }

            // select the image view
            Ion.with(holder.thumb)
                    .resize(300, 300)
                    .centerCrop()
                            //.placeholder(R.drawable.placeholder)
                            //.error(R.drawable.error)
                    .load(getItem(position).get("thumb_url").getAsString());

            holder.name.setText(getItem(position).get("name").getAsString());

            return convertView;
        }

    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

        Log.i(TAG, "parent ==> " + parent.toString());
        Log.i(TAG, "view ==> " + view.toString());

        if (mListener != null) {
            Log.i(TAG, "call to onUserSelection ==> " +
                    mDataFromServer.get(position).getAsJsonObject().toString());
            mListener.onUserSelection(mDataFromServer.get(position).getAsJsonObject());
        }
    }

    public interface OnFragmentInteractionListener {
        public void onUserSelection(JsonObject mUserInfo);
    }

}

.

Answer 1

Non hai inizializzato il tuo valore mListener.Il tuo MListener è nullo e non succede nulla quando fai clic su un elemento ListView.