onback pressed data not showing in fragments

Question

I am using navigation drawer in my app,I have fragments like F1,F2 and so on..and in every fragment I am parsing data and display in listview,everything is works fine if I go through my app like F1>F2>F3 and so on..but the issue is if I go from F3 to F2,the data which I had in my F2 fragments is not showing,and display only blank page,what is the issue?Can any one help?

My F1

public class Categriesdrawers extends Fragment{

    private ImageView drwr;
    private SlidingDrawer sldrwr;

    private ProgressDialog pDialog;
    JSONArray categorylist=null;
    private ListView listview;
    private ArrayList<HashMap<String,String>> aList;
    private static String INTEREST_ACCEPT_URL = "http:.ashx?action=category";
    private static final String INTEREST_ACCEPT="categorylist";
    private static final String INTERESTACCEPT_USER_ID="Id";
    private static final String INTEREST_ACCEPT_NAME="categoryname";

    private CustomAdapterCatagory adapter;
    private TextView noacpt;


    private ListView catlist;

    @SuppressWarnings("deprecation")
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View v=inflater.inflate(R.layout.tests, container, false);

        drwr=(ImageView)v.findViewById(R.id.handle);
        sldrwr=(SlidingDrawer)v.findViewById(R.id.bottom);

        sldrwr.open();
        new LoadAlbums().execute();
            sldrwr.setOnDrawerOpenListener(new OnDrawerOpenListener() {

            @Override
            public void onDrawerOpened() {


                new LoadAlbums().execute();



            }
        });


            catlist=(ListView)v.findViewById(R.id.substitute_list);


            catlist.setOnItemClickListener(new OnItemClickListener() {

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

                    Organization tf = new Organization();

                     Bundle bundle = new Bundle();

                        tf.setArguments(bundle);
                       FragmentManager fm = getFragmentManager();
                       FragmentTransaction ft = fm.beginTransaction();
                       ft.replace(R.id.mainContent, tf);
                       ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
                       ft.addToBackStack(null);
                       ft.commit();

                }
            });


        return v;
    }

    class LoadAlbums extends AsyncTask<String, String, ArrayList<HashMap<String,String>>> {
        /**
         * Before starting background thread Show Progress Dialog
         * */
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(Categriesdrawers.this.getActivity());
            pDialog.setMessage("Loading...");
            pDialog.setIndeterminate(true);
            pDialog.setIndeterminateDrawable(getResources().getDrawable(R.drawable.custom_progress));
            pDialog.setCancelable(false);
            pDialog.show();
        }
        protected ArrayList<HashMap<String,String>> doInBackground(String... args) {
            ServiceHandler sh = new ServiceHandler();
            // Making a request to url and getting response
            ArrayList<HashMap<String,String>> data = new ArrayList<HashMap<String, String>>();
            String jsonStr = sh.makeServiceCall(INTEREST_ACCEPT_URL, ServiceHandler.GET);

            Log.d("Response: ", "> " + jsonStr);

            if (jsonStr != null) {
                try {
                    JSONObject jsonObj = new JSONObject(jsonStr);

                    // Getting JSON Array node
                    categorylist = jsonObj.getJSONArray(INTEREST_ACCEPT);

                    for (int i = 0; i < categorylist.length(); i++) {
                        JSONObject c = categorylist.getJSONObject(i);
                        // creating new HashMap
                        HashMap<String, String> map = new HashMap<String, String>();
                        // adding each child node to HashMap key => value
                        map.put(INTERESTACCEPT_USER_ID, c.getString(INTERESTACCEPT_USER_ID));
                        map.put(INTEREST_ACCEPT_NAME,c.getString(INTEREST_ACCEPT_NAME));

                        // adding HashList to ArrayList
                        data.add(map);
                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            } else {
                Log.e("ServiceHandler", "Couldn't get any data from the url");
            }
            return data;
        }
        protected void onPostExecute(ArrayList<HashMap<String,String>> result) {
            super.onPostExecute(result);

            // dismiss the dialog after getting all albums
            if (pDialog.isShowing())
                pDialog.dismiss();
            // updating UI from Background Thread
            if(aList == null){
                aList = new ArrayList<HashMap<String, String>>();
                aList.addAll(result);
                adapter = new CustomAdapterCatagory(getActivity(),result);
                catlist.setAdapter(adapter);
            }else{
                aList.addAll(result);
                adapter.notifyDataSetChanged();
            }
        }

    }

MainActivity

public class MainActivity extends Activity {
    ListView mDrawerList;
    RelativeLayout mDrawerPane;
    private ActionBarDrawerToggle mDrawerToggle;
    private DrawerLayout mDrawerLayout;
     private CharSequence mTitle;
    ArrayList<NavItem> mNavItems = new ArrayList<NavItem>();
      private CharSequence mDrawerTitle;
ActionBar actionBar;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        actionBar=getActionBar();
        actionBar.setBackgroundDrawable(new ColorDrawable(Color.argb(255, 235, 139, 36)));
        mTitle = mDrawerTitle = getTitle();
        mNavItems.add(new NavItem("All Post",  R.drawable.allpost));
        mNavItems.add(new NavItem("Categories",  R.drawable.allpost));
        mNavItems.add(new NavItem("All Bloggers",  R.drawable.allpost));

        mNavItems.add(new NavItem("About Us",  R.drawable.about));
        mNavItems.add(new NavItem("Rate US",  R.drawable.rates));

     // DrawerLayout
        mDrawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);
     // Populate the Navigtion Drawer with options
        mDrawerPane = (RelativeLayout) findViewById(R.id.drawerPane);
        mDrawerList = (ListView) findViewById(R.id.navList);
        DrawerListAdapter adapter = new DrawerListAdapter(this, mNavItems);
        mDrawerList.setAdapter(adapter);
        mDrawerList.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1, int position,
                    long arg3) {
                 selectItemFromDrawer(position);

            }
        });
        getActionBar().setDisplayHomeAsUpEnabled(true);
        mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
                R.drawable.ic_view, //nav menu toggle icon
                R.string.app_name, // nav drawer open - description for accessibility
                R.string.app_name // nav drawer close - description for accessibility
        ) {
            public void onDrawerClosed(View view) {
                getActionBar().setTitle(mTitle);
                // calling onPrepareOptionsMenu() to show action bar icons
                invalidateOptionsMenu();
            }

            public void onDrawerOpened(View drawerView) {
                getActionBar().setTitle(mDrawerTitle);
                // calling onPrepareOptionsMenu() to hide action bar icons
                invalidateOptionsMenu();
            }
        };
        mDrawerLayout.setDrawerListener(mDrawerToggle);
        if(savedInstanceState==null)
        {
            selectItemFromDrawer(0);
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
         if (mDrawerToggle.onOptionsItemSelected(item)) {
                return true;
            }
            // Handle action bar actions click
            switch (item.getItemId()) {
            case R.id.action_settings:
                return true;
            default:
                return super.onOptionsItemSelected(item);
            }
    }


private void selectItemFromDrawer(int position) {

        Fragment fragment=null;
        switch (position) {
        case 0:
            fragment=new AllPost();
            break;
        case 1:
            fragment=new Categriesdrawers();
            break;

        case 2:
            fragment=new AllBloggerList();
            break;

        /*case 3:
            fragment=new Aboutus();
            break;
        */

        default:
            break;
        }
        if(fragment!=null)
        {
             FragmentManager fragmentManager = getFragmentManager();
            fragmentManager.beginTransaction()
            .replace(R.id.mainContent, fragment)
            .commit();

    mDrawerList.setItemChecked(position, true);
    setTitle(mNavItems.get(position).mTitle);
    mDrawerLayout.closeDrawer(mDrawerPane);
        }
        /*Fragment fragment = new PreferencesFragment();

        FragmentManager fragmentManager = getFragmentManager();
        fragmentManager.beginTransaction()
                .replace(R.id.mainContent, fragment)
                .commit();

        mDrawerList.setItemChecked(position, true);
        setTitle(mNavItems.get(position).mTitle);

        // Close the drawer
        mDrawerLayout.closeDrawer(mDrawerPane);*/
    }

    class NavItem {
        String mTitle;
        String mSubtitle;
        int mIcon;

        public NavItem(String title, int icon) {
            mTitle = title;

            mIcon = icon;
        }
    }
    class DrawerListAdapter extends BaseAdapter {

        Context mContext;
        ArrayList<NavItem> mNavItems;

        public DrawerListAdapter(Context context, ArrayList<NavItem> navItems) {
            mContext = context;
            mNavItems = navItems;
        }

        @Override
        public int getCount() {
            return mNavItems.size();
        }

        @Override
        public Object getItem(int position) {
            return mNavItems.get(position);
        }

        @Override
        public long getItemId(int position) {
            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View view;

            if (convertView == null) {
                LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                view = inflater.inflate(R.layout.drawer_item, null);
            }
            else {
                view = convertView;
            }

            TextView titleView = (TextView) view.findViewById(R.id.title);

            ImageView iconView = (ImageView) view.findViewById(R.id.icon);

            titleView.setText( mNavItems.get(position).mTitle );

            iconView.setImageResource(mNavItems.get(position).mIcon);

            return view;
        }
    }

    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onPostCreate(savedInstanceState);
           mDrawerToggle.syncState();
    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        // TODO Auto-generated method stub
        super.onConfigurationChanged(newConfig);
          mDrawerToggle.onConfigurationChanged(newConfig);
    }

    @Override
    public void setTitle(CharSequence title) {
         mTitle = title;
            getActionBar().setTitle(mTitle);
    }

     @Override
        public void onBackPressed() {
            if (getFragmentManager().getBackStackEntryCount() > 0) {
                getFragmentManager().popBackStack();
            } else {
                super.onBackPressed();
            }
        }
}

Conny

Are you adding these fragments to the backstack? Also please post some screenshots. – Softpedal

nvm the problem is with your F2 and F3. Post their code as well. – Softpedal

same code i have in fragments of F2 and F3 – Conny

What's the point of having 3 classes with the same code? O_@ – Softpedal

in every fragment i am displaying different data with different webservices..like f1 have catagories,f2 have org etc etc – Conny

Please post your main activity code. – Seem

Add all the fragment into stack by using tag – Austerlitz

can you give example – Conny

@Johnson have you checked my code github.com/rathodchintan/Fragment-Back-Stack – Northeasterly

@ChintanRathod but i am using json parsing..and listivew becoms null. – Conny

its becoming null coz you are adding fragment over others. – Northeasterly

Answer 1

Please call addToBackStack(null) when you perform fragment transaction.

fragmentManager.beginTransaction()
            .replace(R.id.mainContent, fragment)
            .addToBackStack(null)
            .commit();

Seem

its alraedy there..can you see? – Conny

It's not there in selectItemFromDrawer() function in your MainActivity – Seem

there is no call to addToBackStack(null). Please see the code in my answer – Seem

yes i got it..so need to remove that code after switch case and paste it to in selectitem from drawer() function?? – Conny

as I see it is already inside that function, just add ".addToBackStack()" there – Seem

Let us continue this discussion in chat. – Conny

Answer 2

Please update your OnCreateView() as below:

public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
        if (view != null) {
        if (view.getParent() != null) {
            ((ViewGroup)view.getParent()).removeView(view);
        }
        return view;
    }

    View v=inflater.inflate(R.layout.tests, container, false);

I hope this helps

Elkin

can you at least complete it ? what's view? on the line -> if (view != null) { confusing. – Tecu