androidx下的fragment的lazy懒加载问题详解

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  >

  <androidx.viewpager.widget.ViewPager
    android:id="@ id/vp_fragment"
    android:layout_width="match_parent"
    android:layout_height="200dp"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    />

  <com.flyco.tablayout.CommonTabLayout
    android:id="@ id/tab_title"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:background="@color/colorPrimary"
    app:tl_indicator_color="@color/colorAccent"
    app:tl_indicator_height="2dp"
    app:tl_indicator_width="30dp"
    app:tl_tab_space_equal="true"
    app:tl_textBold="SELECT"
    app:tl_textSelectColor="#000000"
    app:tl_textUnselectColor="#333333"
    app:layout_constraintTop_toBottomOf="@id/vp_fragment"
    app:layout_constraintLeft_toLeftOf="parent"
    />

  <FrameLayout
    android:id="@ id/fl_in_content"
    android:layout_width="match_parent"
    android:layout_height="200dp"
    app:layout_constraintTop_toBottomOf="@id/tab_title"
    />

  <TextView
    android:id="@ id/tv_next"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:text="next"
    android:gravity="center"
    app:layout_constraintBottom_toBottomOf="parent"
    />

</androidx.constraintlayout.widget.ConstraintLayout>

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:app="http://schemas.android.com/apk/res-auto"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  tools:context=".lazyFragment.ViewPagerFragmentActivity">

  <FrameLayout
    android:id="@ id/fl_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    />

</androidx.constraintlayout.widget.ConstraintLayout>

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  >

  <TextView
    android:id="@ id/tv_fragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:text="" />

</FrameLayout>

/**
 * viewpager内的fragment懒加载
 */
public class ViewPagerFragmentActivity extends BindActivity implements BlankFragment1.OnFragmentInteractionListener , BlankFragment2.OnFragmentInteractionListener, BlankFragment3.OnFragmentInteractionListener {

  private static final String KEY_FRAGMENT_1 = "1";
  private static final String KEY_FRAGMENT_2 = "2";
  private static final String KEY_FRAGMENT_3 = "3";
  @BindView(R.id.vp_fragment)
  ViewPager vp;
  @BindView(R.id.tv_next)
  TextView tv_next;
  BlankFragment1 blankFragment1;
  BlankFragment2 blankFragment2;
  BlankFragment3 blankFragment3;
  List<Fragment> fragmentList;
  @Override
  protected int setLayoutID() {
    return R.layout.fragment_main;
  }

  @Override
  protected void initViews(Bundle savedInstanceState) {

    tv_next.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        Intent intent=new Intent(mContext, MMKVActivity.class);
        startActivity(intent);
      }
    });

    if(savedInstanceState != null){
      blankFragment1 = (BlankFragment1)getSupportFragmentManager().getFragment(savedInstanceState,KEY_FRAGMENT_1);
      blankFragment2 = (BlankFragment2)getSupportFragmentManager().getFragment(savedInstanceState,KEY_FRAGMENT_2);
      blankFragment3 = (BlankFragment3)getSupportFragmentManager().getFragment(savedInstanceState,KEY_FRAGMENT_3);
    }

    fragmentList=new ArrayList<>();
    if (blankFragment1==null){
      fragmentList.add(blankFragment1=BlankFragment1.newInstance("11111",""));
    }else {
      fragmentList.add(blankFragment1);
    }
    if (blankFragment2==null){
      fragmentList.add(blankFragment2=BlankFragment2.newInstance("22222",""));
    }else {
      fragmentList.add(blankFragment2);
    }
    if (blankFragment3==null){
      fragmentList.add(blankFragment3=BlankFragment3.newInstance("333333",""));
    }else {
      fragmentList.add(blankFragment3);
    }

    vp.setAdapter(new BaseFragmentXPagerAdapter(getSupportFragmentManager(),fragmentList,null));

  }

  @Override
  public void onFragmentInteraction(Uri uri) {
  }

  @Override
  protected void onSaveInstanceState(Bundle outState) {
    if(blankFragment1 != null&&blankFragment1.isAdded()) {
      getSupportFragmentManager().putFragment(outState,KEY_FRAGMENT_1,blankFragment1);
    }
    if(blankFragment2 != null&&blankFragment2.isAdded()){
      getSupportFragmentManager().putFragment(outState,KEY_FRAGMENT_2,blankFragment2);
    }
    if(blankFragment3 != null&&blankFragment3.isAdded()){
      getSupportFragmentManager().putFragment(outState,KEY_FRAGMENT_3,blankFragment3);
    }
    super.onSaveInstanceState(outState);
  }
}

@Retention(RetentionPolicy.SOURCE)
  @IntDef({BEHAVIOR_SET_USER_VISIBLE_HINT, BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT})
  private @interface Behavior { }

/**
   * Constructor for {@link FragmentPagerAdapter}.
   *
   * If {@link #BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT} is passed in, then only the current
   * Fragment is in the {@link Lifecycle.State#RESUMED} state. All other fragments are capped at
   * {@link Lifecycle.State#STARTED}. If {@link #BEHAVIOR_SET_USER_VISIBLE_HINT} is passed, all
   * fragments are in the {@link Lifecycle.State#RESUMED} state and there will be callbacks to
   * {@link Fragment#setUserVisibleHint(boolean)}.
   *
   * @param fm fragment manager that will interact with this adapter
   * @param behavior determines if only current fragments are in a resumed state
   */
  public FragmentPagerAdapter(@NonNull FragmentManager fm,
      @Behavior int behavior) {
    mFragmentManager = fm;
    mBehavior = behavior;
  }

/**
 * support lazy init
 */
public class BaseFragmentXPagerAdapter extends FragmentPagerAdapter {

  private List<Fragment> mFragmentList = new ArrayList<>();
  private List<String> mFragmentTitleList = new ArrayList<>();

  public BaseFragmentXPagerAdapter(@NonNull FragmentManager fm,List<Fragment> fragmentList,List<String> fragmentTitleList) {
    this(fm,fragmentList,fragmentTitleList,BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT);
  }
  public BaseFragmentXPagerAdapter(@NonNull FragmentManager fm,List<Fragment> fragmentList,List<String> fragmentTitleList, int behavior) {
    super(fm, behavior);
    if (fragmentList!=null){
      mFragmentList.addAll(fragmentList);
    }
    if (fragmentTitleList!=null){
      mFragmentTitleList.addAll(fragmentTitleList);
    }
  }

  public BaseFragmentXPagerAdapter(@NonNull FragmentManager fm,Fragment[] fragmentList,String[] fragmentTitleList) {
    this(fm,fragmentList,fragmentTitleList,BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT);
  }
  public BaseFragmentXPagerAdapter(@NonNull FragmentManager fm,Fragment[] fragmentList,String[] fragmentTitleList, int behavior) {
    super(fm, behavior);
    if (fragmentList!=null){
      for (int i = 0; i < fragmentList.length; i  ) {
        mFragmentList.add(fragmentList[i]);
      }
    }
    if (fragmentTitleList!=null){
      for (int i = 0; i < fragmentTitleList.length; i  ) {
        mFragmentTitleList.add(fragmentTitleList[i]);
      }
    }
  }

  @NonNull
  @Override
  public Fragment getItem(int position) {
    if (mFragmentList!=null&&!mFragmentList.isEmpty()){
      return mFragmentList.get(position);
    }else {
      return null;
    }
  }

  @Override
  public int getCount() {
    if (mFragmentList!=null&&!mFragmentList.isEmpty()){
      return mFragmentList.size();
    }else {
      return 0;
    }
  }

  @Nullable
  @Override
  public CharSequence getPageTitle(int position) {
    if (mFragmentTitleList!=null&&!mFragmentTitleList.isEmpty()&&position<mFragmentTitleList.size()){
      return mFragmentTitleList.get(position);
    }else {
      return null;
    }
  }
}

/**
 * fragment内的viewpager内的fragment懒加载
 */
public class ViewPagerFragmentInFragmentActivity extends BindActivity implements ViewPagerFragmentInFragment.OnFragmentInteractionListener ,BlankFragment1.OnFragmentInteractionListener, BlankFragment2.OnFragmentInteractionListener, BlankFragment3.OnFragmentInteractionListener {

  @Override
  protected int setLayoutID() {
    return R.layout.activity_lazy_fragment;
  }

  @Override
  protected void initViews(Bundle savedInstanceState) {
    FragmentTransaction transaction=getSupportFragmentManager().beginTransaction();
    transaction.add(R.id.fl_content, ViewPagerFragmentInFragment.newInstance("",""));
    transaction.commit();
  }

  @Override
  public void onFragmentInteraction(Uri uri) {

  }

  @Override
  protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
  }
}

/**
 * viewpager在一个fragment内
 */
public class ViewPagerFragmentInFragment extends BaseFragment {
  private static final String ARG_PARAM1 = "param1";
  private static final String ARG_PARAM2 = "param2";

  private String mParam1;
  private String mParam2;

  private OnFragmentInteractionListener mListener;

  private static final String KEY_FRAGMENT_1 = "1";
  private static final String KEY_FRAGMENT_2 = "2";
  private static final String KEY_FRAGMENT_3 = "3";

  @BindView(R.id.vp_fragment)
  ViewPager vp;
  @BindView(R.id.tv_next)
  TextView tv_next;
  BlankFragment1 blankFragment1;
  BlankFragment2 blankFragment2;
  BlankFragment3 blankFragment3;
  List<Fragment> fragmentList;

  public ViewPagerFragmentInFragment() {
  }

  public static ViewPagerFragmentInFragment newInstance(String param1, String param2) {
    ViewPagerFragmentInFragment fragment = new ViewPagerFragmentInFragment();
    Bundle args = new Bundle();
    args.putString(ARG_PARAM1, param1);
    args.putString(ARG_PARAM2, param2);
    fragment.setArguments(args);
    return fragment;
  }

  @Override
  public void onSaveInstanceState(@NonNull Bundle outState) {

    if(blankFragment1 != null&&blankFragment1.isAdded()) {
      mActivity.getSupportFragmentManager().putFragment(outState,KEY_FRAGMENT_1,blankFragment1);
    }
    if(blankFragment2 != null&&blankFragment2.isAdded()){
      mActivity.getSupportFragmentManager().putFragment(outState,KEY_FRAGMENT_2,blankFragment2);
    }
    if(blankFragment3 != null&&blankFragment3.isAdded()){
      mActivity.getSupportFragmentManager().putFragment(outState,KEY_FRAGMENT_3,blankFragment3);
    }
    super.onSaveInstanceState(outState);
  }

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

  }

  @Override
  public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    tv_next.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        Intent intent=new Intent(mContext, MMKVActivity.class);
        startActivity(intent);
      }
    });

    if(savedInstanceState != null){
      blankFragment1 = (BlankFragment1)mActivity.getSupportFragmentManager().getFragment(savedInstanceState,KEY_FRAGMENT_1);
      blankFragment2 = (BlankFragment2)mActivity.getSupportFragmentManager().getFragment(savedInstanceState,KEY_FRAGMENT_2);
      blankFragment3 = (BlankFragment3)mActivity.getSupportFragmentManager().getFragment(savedInstanceState,KEY_FRAGMENT_3);
    }

    fragmentList=new ArrayList<>();
    if (blankFragment1==null){
      fragmentList.add(blankFragment1=BlankFragment1.newInstance("11111",""));
    }else {
      fragmentList.add(blankFragment1);
    }
    if (blankFragment2==null){
      fragmentList.add(blankFragment2=BlankFragment2.newInstance("22222",""));
    }else {
      fragmentList.add(blankFragment2);
    }
    if (blankFragment3==null){
      fragmentList.add(blankFragment3=BlankFragment3.newInstance("333333",""));
    }else {
      fragmentList.add(blankFragment3);
    }

    vp.setAdapter(new BaseFragmentXPagerAdapter(mActivity.getSupportFragmentManager(),fragmentList,null));

  }

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
               Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment_main, container, false);
  }

  public void onButtonPressed(Uri uri) {
    if (mListener != null) {
      mListener.onFragmentInteraction(uri);
    }
  }

  @Override
  public void onAttach(Context context) {
    super.onAttach(context);
    if (context instanceof OnFragmentInteractionListener) {
      mListener = (OnFragmentInteractionListener) context;
    } else {
      throw new RuntimeException(context.toString()
            " must implement OnFragmentInteractionListener");
    }
  }

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

  public interface OnFragmentInteractionListener {
    void onFragmentInteraction(Uri uri);
  }
}

/**
 * add show hide下的fragment懒加载
 */
public class AddShowHideFragmentActivity extends BindActivity implements BlankFragment1.OnFragmentInteractionListener , BlankFragment2.OnFragmentInteractionListener, BlankFragment3.OnFragmentInteractionListener {

  private static final String KEY_FRAGMENT_1 = "1";
  private static final String KEY_FRAGMENT_2 = "2";
  private static final String KEY_FRAGMENT_3 = "3";
  @BindView(R.id.tab_title)
  CommonTabLayout commonTabLayout;
  @BindView(R.id.tv_next)
  TextView tv_next;
  BlankFragment1 blankFragment1;
  BlankFragment2 blankFragment2;
  BlankFragment3 blankFragment3;
  List<Fragment> fragmentList;
  @Override
  protected int setLayoutID() {
    return R.layout.fragment_main;
  }

  @Override
  protected void initViews(Bundle savedInstanceState) {
    tv_next.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        Intent intent=new Intent(mContext, MMKVActivity.class);
        startActivity(intent);
      }
    });
    if(savedInstanceState != null){
      blankFragment1 = (BlankFragment1)getSupportFragmentManager().getFragment(savedInstanceState,KEY_FRAGMENT_1);
      blankFragment2 = (BlankFragment2)getSupportFragmentManager().getFragment(savedInstanceState,KEY_FRAGMENT_2);
      blankFragment3 = (BlankFragment3)getSupportFragmentManager().getFragment(savedInstanceState,KEY_FRAGMENT_3);
    }
    fragmentList=new ArrayList<>();
    if (blankFragment1==null){
      fragmentList.add(blankFragment1=BlankFragment1.newInstance("11111",""));
    }else {
      fragmentList.add(blankFragment1);
    }
    if (blankFragment2==null){
      fragmentList.add(blankFragment2=BlankFragment2.newInstance("22222",""));
    }else {
      fragmentList.add(blankFragment2);
    }
    if (blankFragment3==null){
      fragmentList.add(blankFragment3=BlankFragment3.newInstance("33333",""));
    }else {
      fragmentList.add(blankFragment3);
    }
    ArrayList<CustomTabEntity> tabEntities = new ArrayList<>();
    tabEntities.add(new TabLayoutEntity("商品1"));
    tabEntities.add(new TabLayoutEntity("评价2"));
    tabEntities.add(new TabLayoutEntity("详情3"));
    commonTabLayout.setTabData(tabEntities);
    commonTabLayout.setCurrentTab(0);
    showFragment(fragmentList.get(0),false);
    commonTabLayout.setOnTabSelectListener(new OnTabSelectListener() {
      @Override
      public void onTabSelect(int position) {
        showFragment(fragmentList.get(position),false);
      }

      @Override
      public void onTabReselect(int position) {
        showFragment(fragmentList.get(position),false);
      }
    });

  }

  private void showFragment(Fragment fragment,boolean replace){
    FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
    if (replace){
      transaction.replace(R.id.fl_in_content,fragment);
    }else {
      if (!fragment.isAdded()){
        transaction.add(R.id.fl_in_content,fragment,fragment.getClass().getSimpleName());
      }
      hideAllFragment(transaction,fragment);
      transaction.show(fragment);
      transaction.setMaxLifecycle(fragment, Lifecycle.State.RESUMED);
    }
    transaction.commit();
  }
  private void hideAllFragment(FragmentTransaction transaction,Fragment withoutFragment){
    for (int i = 0; i < fragmentList.size(); i  ) {
      if (!fragmentList.get(i).equals(withoutFragment)&&fragmentList.get(i).isAdded()){
        transaction.hide(fragmentList.get(i));
        transaction.setMaxLifecycle(fragmentList.get(i), Lifecycle.State.CREATED);
      }
    }
  }

  @Override
  public void onFragmentInteraction(Uri uri) {
  }

  @Override
  protected void onSaveInstanceState(Bundle outState) {
    if(blankFragment1 != null&&blankFragment1.isAdded()) {
      getSupportFragmentManager().putFragment(outState,KEY_FRAGMENT_1,blankFragment1);
    }
    if(blankFragment2 != null&&blankFragment2.isAdded()){
      getSupportFragmentManager().putFragment(outState,KEY_FRAGMENT_2,blankFragment2);
    }
    if(blankFragment3 != null&&blankFragment3.isAdded()){
      getSupportFragmentManager().putFragment(outState,KEY_FRAGMENT_3,blankFragment3);
    }
    super.onSaveInstanceState(outState);
  }
}

/**
 * fragment内的viewpager内的fragment懒加载
 */
public class AddShowHideFragmentInFragmentActivity extends BindActivity implements AddFragmentInFragment.OnFragmentInteractionListener ,BlankFragment1.OnFragmentInteractionListener, BlankFragment2.OnFragmentInteractionListener, BlankFragment3.OnFragmentInteractionListener {

  @Override
  protected int setLayoutID() {
    return R.layout.activity_lazy_fragment;
  }

  @Override
  protected void initViews(Bundle savedInstanceState) {
    FragmentTransaction transaction=getSupportFragmentManager().beginTransaction();
    transaction.add(R.id.fl_content,AddFragmentInFragment.newInstance("",""));
    transaction.commit();
  }

  @Override
  public void onFragmentInteraction(Uri uri) {

  }

  @Override
  protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
  }
}

/**
 * add hide show显示的fragment 嵌套在 外层fragment内
 */
public class AddFragmentInFragment extends BaseFragment {

  private static final String ARG_PARAM1 = "param1";
  private static final String ARG_PARAM2 = "param2";

  private String mParam1;
  private String mParam2;

  private OnFragmentInteractionListener mListener;

  private static final String KEY_FRAGMENT_1 = "1";
  private static final String KEY_FRAGMENT_2 = "2";
  private static final String KEY_FRAGMENT_3 = "3";

  @BindView(R.id.tab_title)
  CommonTabLayout commonTabLayout;
  @BindView(R.id.tv_next)
  TextView tv_next;
  BlankFragment1 blankFragment1;
  BlankFragment2 blankFragment2;
  BlankFragment3 blankFragment3;
  List<Fragment> fragmentList;

  public AddFragmentInFragment() {
  }

  public static AddFragmentInFragment newInstance(String param1, String param2) {
    AddFragmentInFragment fragment = new AddFragmentInFragment();
    Bundle args = new Bundle();
    args.putString(ARG_PARAM1, param1);
    args.putString(ARG_PARAM2, param2);
    fragment.setArguments(args);
    return fragment;
  }

  @Override
  public void onSaveInstanceState(@NonNull Bundle outState) {
    if(blankFragment1 != null&&blankFragment1.isAdded()) {
      mActivity.getSupportFragmentManager().putFragment(outState,KEY_FRAGMENT_1,blankFragment1);
    }
    if(blankFragment2 != null&&blankFragment2.isAdded()){
      mActivity.getSupportFragmentManager().putFragment(outState,KEY_FRAGMENT_2,blankFragment2);
    }
    if(blankFragment3 != null&&blankFragment3.isAdded()){
      mActivity.getSupportFragmentManager().putFragment(outState,KEY_FRAGMENT_3,blankFragment3);
    }
    super.onSaveInstanceState(outState);
  }

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

  }

  @Override
  public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    tv_next.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        Intent intent=new Intent(mContext, MMKVActivity.class);
        startActivity(intent);
      }
    });
    if(savedInstanceState != null){
      blankFragment1 = (BlankFragment1)mActivity.getSupportFragmentManager().getFragment(savedInstanceState,KEY_FRAGMENT_1);
      blankFragment2 = (BlankFragment2)mActivity.getSupportFragmentManager().getFragment(savedInstanceState,KEY_FRAGMENT_2);
      blankFragment3 = (BlankFragment3)mActivity.getSupportFragmentManager().getFragment(savedInstanceState,KEY_FRAGMENT_3);
    }
    fragmentList=new ArrayList<>();
    if (blankFragment1==null){
      fragmentList.add(blankFragment1=BlankFragment1.newInstance("11111",""));
    }else {
      fragmentList.add(blankFragment1);
    }
    if (blankFragment2==null){
      fragmentList.add(blankFragment2=BlankFragment2.newInstance("222222",""));
    }else {
      fragmentList.add(blankFragment2);
    }
    if (blankFragment3==null){
      fragmentList.add(blankFragment3=BlankFragment3.newInstance("3333333",""));
    }else {
      fragmentList.add(blankFragment3);
    }

    ArrayList<CustomTabEntity> tabEntities = new ArrayList<>();
    tabEntities.add(new TabLayoutEntity("商品1"));
    tabEntities.add(new TabLayoutEntity("评价2"));
    tabEntities.add(new TabLayoutEntity("详情3"));
    commonTabLayout.setTabData(tabEntities);
    commonTabLayout.setCurrentTab(0);
    showFragment(fragmentList.get(0),false);
    commonTabLayout.setOnTabSelectListener(new OnTabSelectListener() {
      @Override
      public void onTabSelect(int position) {
        showFragment(fragmentList.get(position),false);
      }

      @Override
      public void onTabReselect(int position) {
        showFragment(fragmentList.get(position),false);
      }
    });

  }

  private void showFragment(Fragment fragment,boolean replace){
    FragmentTransaction transaction = mActivity.getSupportFragmentManager().beginTransaction();
    if (replace){
      transaction.replace(R.id.fl_in_content,fragment);
    }else {
      if (!fragment.isAdded()){
        transaction.add(R.id.fl_in_content,fragment,fragment.getClass().getSimpleName());
      }
      hideAllFragment(transaction,fragment);
      transaction.show(fragment);
      transaction.setMaxLifecycle(fragment, Lifecycle.State.RESUMED);
    }
    transaction.commit();
  }
  private void hideAllFragment(FragmentTransaction transaction,Fragment withoutFragment){
    for (int i = 0; i < fragmentList.size(); i  ) {
      if (!fragmentList.get(i).equals(withoutFragment)&&fragmentList.get(i).isAdded()){
        transaction.hide(fragmentList.get(i));
        transaction.setMaxLifecycle(fragmentList.get(i), Lifecycle.State.CREATED);
      }
    }
  }

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
               Bundle savedInstanceState) {
    return inflater.inflate(R.layout.fragment_main, container, false);
  }

  public void onButtonPressed(Uri uri) {
    if (mListener != null) {
      mListener.onFragmentInteraction(uri);
    }
  }

  @Override
  public void onAttach(Context context) {
    super.onAttach(context);
    if (context instanceof OnFragmentInteractionListener) {
      mListener = (OnFragmentInteractionListener) context;
    } else {
      throw new RuntimeException(context.toString()
            " must implement OnFragmentInteractionListener");
    }
  }

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

  public interface OnFragmentInteractionListener {
    void onFragmentInteraction(Uri uri);
  }
}