包含recyclerview的TabLayout在另一个标签上滑动时丢失了信息

Question

我在TabLayout中有一个RecyclerView，效果很好。。我充满了RecyclerView的数据，并且效果很好，但是当滑动到其他Tab并返回并返回上一个Tab时，recyclerView中的数据消失了。我做错了什么？

ScheduleAndGuestList.java

public class ScheduleAndGuestList extends AppCompatActivity 

    private TabLayout tabLayout;

    private ViewPager viewPager;

    private TabItem tabSchedale,tabGuests;

    private pageAdapter pagerAdapter;

    private Button btn;

    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_schedule_and_guest_list);

        tabLayout =(TabLayout)findViewById(R.id.tableLayout);

        tabSchedale=(TabItem)findViewById(R.id.tabSchedulePest);
        tabGuests=(TabItem)findViewById(R.id.tabGuestsPest);

        viewPager=findViewById(R.id.viewPager);
        pagerAdapter=new pageAdapter(getSupportFragmentManager(), tabLayout.getTabCount());

        viewPager.setAdapter(pagerAdapter);



        tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() 
            @Override
            public void onTabSelected(TabLayout.Tab tab) 

                if (tab.getPosition() == 0) 
                    pagerAdapter.notifyDataSetChanged();

                 else if (tab.getPosition() == 1) 
                    pagerAdapter.notifyDataSetChanged();

                

            

            @Override
            public void onTabUnselected(TabLayout.Tab tab) 

            

            @Override
            public void onTabReselected(TabLayout.Tab tab) 

            
        );

        viewPager.setOffscreenPageLimit(tabLayout.getTabCount());

        viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));

tabSchedule.java

public class tabSchedule extends Fragment 

    private String horaMin,stringDescrp;

    private Button btn, seleccHora;

    private EditText descrpEt;

    private ImageView img1,img2;

    private HorizontalScrollView scrollView;

    private ArrayList<String> arrayHora,arrayDescrp;

    private RecyclerView recyclerViewtab;

    listScheduleAdapter adapter=new listScheduleAdapter(arrayHora,arrayDescrp);

    public tabSchedule() 
        // Required empty public constructor
    


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) 
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_tab_schedule, container, false);


        btn = (Button) view.findViewById(R.id.button);

        recyclerViewtab=(RecyclerView)view.findViewById(R.id.recyclerViewScheduleId);

        arrayHora=new ArrayList<String>();
        arrayDescrp=new ArrayList<String>();

        //RecyclerView
        recyclerViewtab.setLayoutManager(new LinearLayoutManager(getActivity(),LinearLayoutManager.VERTICAL,false));
        recyclerViewtab.addItemDecoration(new DividerItemDecoration(getActivity(),DividerItemDecoration.VERTICAL));
        adapter=new listScheduleAdapter(arrayHora,arrayDescrp);
        recyclerViewtab.setAdapter(adapter);


        btn.setOnClickListener(new View.OnClickListener() 
            @Override
            public void onClick(View v) 

                AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
                final View view = LayoutInflater.from(getActivity()).inflate(R.layout.alertdialog_addschedule, null);

                scrollView=(HorizontalScrollView)view.findViewById(R.id.scrollView);

                img1=(ImageView)view.findViewById(R.id.img1);
                img2=(ImageView)view.findViewById(R.id.img2);

                //Selecionar hora
                
                    seleccHora = (Button) view.findViewById(R.id.seleccionarHoraSheduleId);

                    seleccHora.setOnClickListener(new View.OnClickListener() 
                        @Override
                        public void onClick(View v) 
                            Calendar mcurrentTime = Calendar.getInstance();
                            int hour = mcurrentTime.get(Calendar.HOUR_OF_DAY);
                            int minute = mcurrentTime.get(Calendar.MINUTE);
                            TimePickerDialog mTimePicker;
                            mTimePicker = new TimePickerDialog(getActivity(), new TimePickerDialog.OnTimeSetListener() 
                                @Override
                                public void onTimeSet(TimePicker timePicker, int selectedHour, int selectedMinute) 
                                    horaMin = String.format("%02d:%02d", selectedHour, selectedMinute);

                                    seleccHora.setText(horaMin);
                                
                            , hour, minute, true);
                            mTimePicker.setTitle("Select Time");
                            mTimePicker.show();
                        
                    );
                

                img1.setOnClickListener(new View.OnClickListener() 
                    @Override
                    public void onClick(View v) 
                        img1.setBackgroundColor(Color.parseColor("#FF4081"));
                        Toast.makeText(getActivity(), "Works 1!", Toast.LENGTH_SHORT).show();
                    
                );

                builder.setTitle("Agregar programacion");
                builder.setPositiveButton("Agregar", new DialogInterface.OnClickListener() 
                    @Override
                    public void onClick(DialogInterface dialog, int which) 

                        descrpEt=(EditText)view.findViewById(R.id.descripScheduleId);
                        stringDescrp=descrpEt.getText().toString();

                        arrayHora.add(horaMin);
                        arrayDescrp.add(stringDescrp);

                        adapter.notifyDataSetChanged();

                    
                ).setNegativeButton("Cancelar", new DialogInterface.OnClickListener() 
                    @Override
                    public void onClick(DialogInterface dialog, int which) 
                    
                );

                builder.setView(view);
                builder.show();

            
        );

        return view;

pageAdapter.java

public class pageAdapter extends FragmentPagerAdapter 

    private int numOfTabs;

    public pageAdapter(@NonNull FragmentManager fm, int numOfTabs) 
        super(fm);
        this.numOfTabs = numOfTabs;
    

    @NonNull
    @Override
    public Fragment getItem(int position) 
        switch (position)
            case 0:
                return new tabSchedule();
            case 1:
                return new tabGuests();
            default:
                return null;
        
    

    @Override
    public int getCount() 
        return numOfTabs;
    

    @Override
    public int getItemPosition(Object object) 
        return POSITION_NONE;

Answer 1

另一答案