Problema con metodo e viewpager del backstack in Android

Question

Ho un'attività che contiene un framelayout.In esso, ho un frammento che contiene il Viewpager con due diversi frammenti all'interno.Quando spingo il pulsante nel frammento dato, sostituisco il contenitore FrameLayout con un nuovo frammento.Ora quando premi indietro la vista del viewpager non viene ripristinata, è sparito.

Questo è il primo frammento:

public class CurrencyFragment extends BaseFragment {


    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setHasOptionsMenu(true);
    }


    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {

        super.onCreateOptionsMenu(menu, inflater);

    }

    // onclick method for the refresh button on the action bar
    // the method itself calls the anoteher method getCurrency()
    // it also sets visibility to progress bar and loading text and
    // sets invisible to the listview

    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.action_refresh:


            Log.i("TAG", "refresh pressed =>");
            return true;
        }
        // Handle your other action bar items...

        return super.onOptionsItemSelected(item);
    }



    // oncreateView() where the basic view is created

    @Override
    public View onCreateView(final LayoutInflater inflater,
            ViewGroup container, Bundle savedInstanceState) {
        final View view = inflater.inflate(R.layout.fragment_currency_layout,
                container, false);



        mBankName = (TextView) view.findViewById(R.id.Currency_name);
        mBuySell = (LinearLayout) view.findViewById(R.id.Buy_Sell);
        mButtonBuy = (TextView) view.findViewById(R.id.Button_buy);
        mButtonSell = (TextView) view.findViewById(R.id.Button_sell);
        mViewpager = (ViewPager) view.findViewById(R.id.Detailpager);



        Bundle bundle = getArguments();
        if(bundle != null){
        Bank object = (Bank) bundle.getSerializable("message");
        mBankName.setText(object.getName());
        code = object.getCode();
        }

        testadapter = new ViewPagerAdapter(getFragmentManager(),code);
        mViewpager.setAdapter(testadapter);

        if(code.equals("NBG")){
            mBuySell.setVisibility(View.GONE);
             mViewpager.setOnTouchListener(new View.OnTouchListener() {

                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    // TODO Auto-generated method stub
                    return false;
                }
            });
        }else{
            mBuySell.setVisibility(View.VISIBLE);
        }

        mViewpager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

            @Override
            public void onPageSelected(int position) {
                // TODO Auto-generated method stub
                if (position == 0){
                    mButtonBuy.setBackgroundColor(Color.parseColor("#2FCEB8"));
                    mButtonSell.setBackgroundColor(Color.parseColor("#333333"));
                }
                else{
                    mButtonSell.setBackgroundColor(Color.parseColor("#2FCEB8"));
                    mButtonBuy.setBackgroundColor(Color.parseColor("#333333"));
                }
            }

            @Override
            public void onPageScrollStateChanged(int arg0) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {
                // TODO Auto-generated method stub

            }


        });





        mButtonBuy.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                mButtonBuy.setBackgroundColor(Color.parseColor("#2FCEB8"));
                mButtonSell.setBackgroundColor(Color.parseColor("#333333"));
                mViewpager.setCurrentItem(0);



            }
        });

        mButtonSell.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                mButtonSell.setBackgroundColor(Color.parseColor("#2FCEB8"));
                mButtonBuy.setBackgroundColor(Color.parseColor("#333333"));
                mViewpager.setCurrentItem(1);


            }
        });

        return view;

    }  

}

.

dopo viene sostituito con l'altro

public class DetailedCalculator extends BaseFragment {

    private View detailedView;
    private TextView mButtonBuy;
    private TextView mButtonSell;
    private TextView mDetailedBank;
    private ViewPager mDetailpager;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub

        DetailPagerAdapter myAdapter = new DetailPagerAdapter(getFragmentManager());

        detailedView = inflater.inflate(R.layout.detail_buy_sell, container, false);
        mButtonBuy = (TextView) detailedView.findViewById(R.id.Detail_buying);
        mButtonSell = (TextView) detailedView.findViewById(R.id.Detail_selling);
        mDetailedBank = (TextView) detailedView.findViewById(R.id.Detail_BankNAme);

        mDetailpager = (ViewPager) detailedView.findViewById(R.id.Detailpager);
        mDetailpager.setAdapter(myAdapter);


        mDetailpager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

            @Override
            public void onPageSelected(int position) {
                // TODO Auto-generated method stub
                if(position == 0){
                    mButtonBuy.setBackgroundColor(Color.parseColor("#2FCEB8"));
                    mButtonSell.setBackgroundColor(Color.parseColor("#333333"));
                }
                else{
                    mButtonSell.setBackgroundColor(Color.parseColor("#2FCEB8"));
                    mButtonBuy.setBackgroundColor(Color.parseColor("#333333"));
                }
            }

            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {
                // TODO Auto-generated method stub

            }

            @Override
            public void onPageScrollStateChanged(int arg0) {
                // TODO Auto-generated method stub

            }
        });

        mButtonBuy.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                mButtonBuy.setBackgroundColor(Color.parseColor("#2FCEB8"));
                mButtonSell.setBackgroundColor(Color.parseColor("#333333"));
                mDetailpager.setCurrentItem(0);
            }
        });

        mButtonSell.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                mButtonSell.setBackgroundColor(Color.parseColor("#2FCEB8"));
                mButtonBuy.setBackgroundColor(Color.parseColor("#333333"));
                mDetailpager.setCurrentItem(1);

            }
        });


        return detailedView;


    }



}

.

Answer 1

Prova ad usare getChildFragmentManager() invece di getFragmentManager() nel frammento contenente il ViewPager:

testadapter = new ViewPagerAdapter(getFragmentManager(),code);

.

a

testadapter = new ViewPagerAdapter(getChildFragmentManager(),code);

.