Проблема с TabLayout в фрагменте (android/java)

Question

Я попытался добавить tabLayout в свое приложение. Когда я открываю фрагмент (там, где есть мой tablayout), он работает нормально, но если я закрою фрагмент, и я попытаюсь его снова открыть, индикатор вкладки не будет следовать за моим ударом, и все viewPager станет пустым. .. как я могу решить эту проблему?

мой фрагмент:

package com.gabrielemarcozzi.mycal; 

import android.app.Activity; 
import android.net.Uri; 
import android.os.Bundle; 
import android.app.Fragment; 
import android.support.design.widget.TabLayout; 
import android.support.v4.app.FragmentActivity; 
import android.support.v4.app.FragmentManager; 
import android.support.v4.app.FragmentPagerAdapter; 
import android.support.v4.view.ViewPager; 
import android.support.v7.widget.Toolbar; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 

public class PercentageFragment extends Fragment { 
// TODO: Rename parameter arguments, choose names that match 
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER 
private static final String ARG_PARAM1 = "param1"; 
private static final String ARG_PARAM2 = "param2"; 

// TODO: Rename and change types of parameters 
private String mParam1; 
private String mParam2; 

private OnFragmentInteractionListener mListener; 

/** 
* Use this factory method to create a new instance of 
* this fragment using the provided parameters. 
* 
* @param param1 Parameter 1. 
* @param param2 Parameter 2. 
* @return A new instance of fragment PercentageFragment. 
*/ 
// TODO: Rename and change types and number of parameters 
public static PercentageFragment newInstance(String param1, String param2) { 
    PercentageFragment fragment = new PercentageFragment(); 
    Bundle args = new Bundle(); 
    args.putString(ARG_PARAM1, param1); 
    args.putString(ARG_PARAM2, param2); 
    fragment.setArguments(args); 
    return fragment; 
} 

public PercentageFragment() { 
    // Required empty public constructor 
} 

private FragmentActivity context; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    if (getArguments() != null) { 
     mParam1 = getArguments().getString(ARG_PARAM1); 
     mParam2 = getArguments().getString(ARG_PARAM2); 
    } 
} 

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

    Toolbar mToolbar = (Toolbar)getActivity().findViewById(R.id.toolbar); 
    mToolbar.setTitle(R.string.percentage); 

    ViewPager percentagePager = (ViewPager)view.findViewById(R.id.percentage_pager); 
    percentagePager.setAdapter(new PercentagePagerAdapter(context.getSupportFragmentManager())); 

    TabLayout percentageTab = (TabLayout)view.findViewById(R.id.percentage_tabs); 
    percentageTab.setupWithViewPager(percentagePager); 

    return view; 
} 

// TODO: Rename method, update argument and hook method into UI event 
public void onButtonPressed(Uri uri) { 
    if (mListener != null) { 
     mListener.onFragmentInteraction(uri); 
    } 
} 

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

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

/** 
* This interface must be implemented by activities that contain this 
* fragment to allow an interaction in this fragment to be communicated 
* to the activity and potentially other fragments contained in that 
* activity. 
* <p/> 
* See the Android Training lesson <a href= 
* "http://developer.android.com/training/basics/fragments/communicating.html" 
* >Communicating with Other Fragments</a> for more information. 
*/ 
public interface OnFragmentInteractionListener { 
    // TODO: Update argument type and name 
    public void onFragmentInteraction(Uri uri); 
} 

class PercentagePagerAdapter extends FragmentPagerAdapter { 

    String[] pergentageTabsArray; 

    public PercentagePagerAdapter(FragmentManager fm) { 
     super(fm); 
     pergentageTabsArray = getResources().getStringArray(R.array.percentage_tabs); 
    } 

    @Override 
    public android.support.v4.app.Fragment getItem(int position) { 
     TabsPercentageFragment TabsPercFrag = TabsPercentageFragment.getIstance(position); 
     return TabsPercFrag; 
    } 

    @Override 
    public CharSequence getPageTitle(int position) { 
     return pergentageTabsArray[position]; 
    } 

    @Override 
    public int getCount() { 
     return 3; 
    } 
} 

public static class TabsPercentageFragment extends android.support.v4.app.Fragment { 

    public static TabsPercentageFragment getIstance(int position) { 
     TabsPercentageFragment increaseFrag = new TabsPercentageFragment(); 
     Bundle args = new Bundle(); 
     args.putInt("position", position); 
     increaseFrag.setArguments(args); 
     return increaseFrag; 
    } 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
          Bundle savedInstanceState) { 
     View view; 
     Bundle bundle = getArguments(); 
     switch(bundle.getInt("position")) { 
      case 1: 
       view = inflater.inflate(R.layout.fragment_discount, container, false); 
       break; 
      case 2: 
       view = inflater.inflate(R.layout.fragment_xofy, container, false); 
       break; 
      default: 
       view =inflater.inflate(R.layout.fragment_increase, container, false); 
       break; 
     } 

     return view; 
    } 
} 

}

мой файл фрагмент XML:

<LinearLayout 
    android:id="@+id/percentage_fragment" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:orientation="vertical" 
    tools:context="com.gabrielemarcozzi.mycal.PercentageFragment"> 

    <android.support.design.widget.TabLayout 
     android:id="@+id/percentage_tabs" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:background="@color/colorPrimary" 
     app:tabMode="fixed" 
     app:tabIndicatorColor="@color/colorUp" 
     app:tabTextColor="@android:color/white" 
     app:tabSelectedTextColor="@color/colorUp"/> 

    <android.support.v4.view.ViewPager 
     android:id="@+id/percentage_pager" 
     android:layout_width="match_parent" 
     android:layout_height="0dp" 
     android:layout_weight="1"/> 

    <!-- TODO: Update blank fragment layout --> 

</LinearLayout> 

Answer 1

Попробуйте пользователя getChildFragmentManager() вместо из getSupportFragmentManager() по адресу:

percentagePager.setAdapter(new PercentagePagerAdapter(context.getSupportFragmentManager())); 

и изменить свой импорт из: import android.app.Fragment;

к

import android.support.v4.app.Fragment;