onCreateView, her zaman viewPagerAdapter.addTab()

Question

'dan sonra çağrılmaz Dinamik ekleme/kaldırma sekmeleri seçeneği ile uygulama oluşturmak istiyorum ve bir şeyle ilgili sorun yaşıyorum.

Sekmeler eklerken ilk kez her şey tamam, ancak bir sekmeyi kaldırdığımda ve tekrar yeni sekme eklemek istediğimde, o yeni parçada onCreateView yok.

Örnek:

ben eklemek yeni 3 sekmeleri:

• sekme 1 ekleyin: onCreateView denir

ViewPagerAdapter vpa = (ViewPagerAdapter) mViewPager.getAdapter(); 
vpa.addTab("TAB 1"); 
vpa.notifyDataSetChanged(); 

.

some logs: 
    [add tab] mViewPager.getChildCount() = 1 
    [add tab] vpa.getCount() = 1 

• sekme 2 ekleyin: onCreateView

vpa.addTab("TAB 2"); 
vpa.notifyDataSetChanged(); 

denir.

some logs: 
    [add tab] mViewPager.getChildCount() = 2 
    [add tab] vpa.getCount() = 2 

• sekme 3 ekleyin: onCreateView

vpa.addTab("TAB 3"); 
vpa.notifyDataSetChanged(); 

denir.

some logs: 
    [add tab] mViewPager.getChildCount() = 3 
    [add tab] vpa.getCount() = 3 

• şimdi Tab 2 silmek istiyorum:

vpa.removeTab("TAB 2"); 
vpa.notifyDataSetChanged(); 

some logs: 
    [add tab] mViewPager.getChildCount() = 2 
    [add tab] vpa.getCount() = 2 

• ve tekrar Tab 2 eklemek istiyorum:

vpa.addTab("TAB 2"); 
vpa.notifyDataSetChanged(); 

ve denilen hiçbir onCreateView :(

some logs: 
    [add tab] mViewPager.getChildCount() = 2 
    [add tab] vpa.getCount() = 3 

herkes bunu düzeltmek için bilmek Can var mı? Neden onCreateView her zaman aranmaz?

Uygulama kodu:

private void initViewpagerAndTabs(){ 
    mViewPager = (ViewPager) findViewById(R.id.viewpager_slave); 
    mViewPager.setOffscreenPageLimit(10); 
    mAdapterViewPager = new ViewPagerAdapter(getSupportFragmentManager()); 
    mViewPager.setAdapter(mAdapterViewPager); 
    mTabLayout = (TabLayout) findViewById(R.id.tabLayout_slave); 
    mTabLayout.setupWithViewPager(mViewPager); 
} 

/** Tabs content fragment */ 
public static class DummyFragment extends Fragment implements RecyclerAdapter.ViewHolder.ClickListener { 
    private RecyclerView mRecyclerView; 
    private RecyclerAdapter mAdapterRecycler; 
    private RecyclerView.LayoutManager mLayoutManager; 
    private Fab fab; 

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

     //setRetainInstance(true); 
     initRecyclerView(view); 
     fab = (Fab) getActivity().findViewById(R.id.fabRemoveItems); 

     return view; 
    } 

    private void initRecyclerView(View view){ 
     mRecyclerView = (RecyclerView) view.findViewById(R.id.recycler_view_slave); 

     // use this setting to improve performance if you know that changes 
     // in content do not change the layout size of the RecyclerView 
     mRecyclerView.setHasFixedSize(true); 

     mLayoutManager = new LinearLayoutManager(getContext()); 
     mRecyclerView.setLayoutManager(mLayoutManager); 
     RecyclerView.ItemAnimator itemAnimator = mRecyclerView.getItemAnimator(); 
     itemAnimator.setAddDuration(500); 
     itemAnimator.setRemoveDuration(500); 

     mAdapterRecycler = new RecyclerAdapter(this); 
     mRecyclerView.setAdapter(mAdapterRecycler); 
    } 

} 

private class ViewPagerAdapter extends FragmentStatePagerAdapter { 
    private final List<DummyFragment> mFragmentList = new ArrayList<>(); 
    private final List<String> mFragmentTitleList = new ArrayList<>(); 

    public ViewPagerAdapter(FragmentManager fm) { 
     super(fm); 
    } 

    public DummyFragment getItem(int num) throws IndexOutOfBoundsException{ 
     return mFragmentList.get(num); 
    } 

    public void addTab(String title) throws Exception { 
     if(isTabExist(title)){ 
      throw new Exception("Tabs already exist!"); 
     } 
     //Log.d(TAG, "[addTab] mFragmentTitleList before add: " + mFragmentTitleList); 
     //Log.d(TAG, "[addTab] mFragmentList before add: " + mFragmentList); 
     mFragmentList.add(new DummyFragment()); 
     mFragmentTitleList.add(title); 
     //Log.d(TAG, "[addTab] mFragmentTitleList after add: " + mFragmentTitleList); 
     //Log.d(TAG, "[addTab] mFragmentList after add: " + mFragmentList); 
    } 

    public void removeTab(int position){ 
     //Log.d(TAG, "[removeTab] mFragmentTitleList before removed: " + mFragmentTitleList); 
     //Log.d(TAG, "[removeTab] mFragmentList before removed: " + mFragmentList); 
     mFragmentTitleList.remove(position); 
     mFragmentList.remove(position); 
     //Log.d(TAG, "[removeTab] mFragmentTitleList after removed: " + mFragmentTitleList); 
     //Log.d(TAG, "[removeTab] mFragmentList after removed: " + mFragmentList); 
    } 

    private boolean isTabExist(String name){ 
     for(int i = 0; i < mFragmentTitleList.size(); i++) { 
      if (mFragmentTitleList.get(i).equals(name)) { 
       return true; 
      } 
     } 
     return false; 
    } 

    public int getTabPosition(String tabName) throws IndexOutOfBoundsException{ 
     for(int i = 0; i < mFragmentTitleList.size(); i++) { 
      if (mFragmentTitleList.get(i).equals(tabName)) { 
       return i; 
      } 
     } 
     throw new IndexOutOfBoundsException(); 
    } 

    @Override 
    public void destroyItem(ViewGroup container, int position, Object object) { 
     super.destroyItem(container, position, object); 
     getSupportFragmentManager().beginTransaction().remove((Fragment) object) 
       .commit(); 
    } 

    @Override 
    public int getItemPosition(Object object) { 
     if (mFragmentList.contains(object)) return mFragmentList.indexOf(object); 
     else return POSITION_NONE; 
    } 

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

    @Override 
    public CharSequence getPageTitle(int position) { 
     return mFragmentTitleList.get(position); 
    } 
} 

Answer 1

Tamam, bu sorunu çözmek.

Sil:

mViewPager.setOffscreenPageLimit(10); 

geçersiz kılma yöntemleri fragmanları durumunu kaydetmek için:

public void onViewStateRestored(@Nullable Bundle savedInstanceState) 

public void onSaveInstanceState(Bundle outState) 

Ve ben kendi FragmentStatePagerAdapter sınıfı oluşturduk. Silinen sekmede parça durumu kaydetmem gerekiyordu.

Kodu:

public class FragStatePagerAdaper extends PagerAdapter { 

    private static final String TAG = "FragStatePagerAdapter"; 
    private static final boolean DEBUG = true; 

    private final FragmentManager mFragmentManager; 
    private FragmentTransaction mCurTransaction = null; 

    private ArrayList<Fragment.SavedState> mSavedState = new ArrayList<Fragment.SavedState>(); 
    /** Cached fragments */ 
    private ArrayList<Fragment> mFragments = new ArrayList<Fragment>(); 
    private Fragment mCurrentPrimaryItem = null; 

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

    public FragStatePagerAdaper(FragmentManager fm) { 
     mFragmentManager = fm; 
    } 

    /** 
    * Return the Fragment associated with a specified position. 
    */ 
    public DummyFragment getItem(int num) throws IndexOutOfBoundsException{ 
     return mFragmentList.get(num); 
    } 

    @Override 
    public void startUpdate(ViewGroup container) { 
    } 

    @Override 
    public Object instantiateItem(ViewGroup container, int position) { 
     // If we already have this item instantiated, there is nothing 
     // to do. This can happen when we are restoring the entire pager 
     // from its saved state, where the fragment manager has already 
     // taken care of restoring the fragments we previously had instantiated. 
     if (mFragments.size() > position) { 
      Fragment f = mFragments.get(position); 
      if (f != null) { 
       return f; 
      } 
     } 

     if (mCurTransaction == null) { 
      mCurTransaction = mFragmentManager.beginTransaction(); 
     } 

     Fragment fragment = getItem(position); 
     if (DEBUG) Log.v(TAG, "Adding item #" + position + ": f=" + fragment); 
     if (mSavedState.size() > position) { 
      Fragment.SavedState fss = mSavedState.get(position); 
      if (fss != null) { 
       fragment.setInitialSavedState(fss); 
      } 
     } 
     while (mFragments.size() <= position) { 
      mFragments.add(null); 
     } 
     fragment.setMenuVisibility(false); 
     fragment.setUserVisibleHint(false); 
     mFragments.set(position, fragment); 
     mCurTransaction.add(container.getId(), fragment); 

     return fragment; 
    } 

    @Override 
    public void destroyItem(ViewGroup container, int position, Object object) { 
     Fragment fragment = (Fragment) object; 

     if (mCurTransaction == null) { 
      mCurTransaction = mFragmentManager.beginTransaction(); 
     } 
     if (DEBUG) Log.v(TAG, "Removing item #" + position + ": f=" + object 
       + " v=" + ((Fragment)object).getView()); 
     while (mSavedState.size() <= position) { 
      mSavedState.add(null); 
     } 

     mSavedState.set(position, fragment.isAdded() 
        ? mFragmentManager.saveFragmentInstanceState(fragment) : null); 

     mFragments.set(position, null); 

     mCurTransaction.remove(fragment); 
    } 

    public void addTab(String title) throws Exception { 
     if(isTabExist(title)){ 
      throw new Exception("Tabs already exist!"); 
     } 
     mFragmentList.add(new DummyFragment()); 
     mFragmentTitleList.add(title); 
    } 

    //look here! 
    public void removeTab(int position){ 
     Log.d(TAG, "removeTab: position = " + position); 
     mFragmentTitleList.remove(position); 
     mFragmentList.remove(position); 
     mSavedState.remove(position); // <---- here! 
    } 

    private boolean isTabExist(String name){ 
     for(int i = 0; i < mFragmentTitleList.size(); i++) { 
      if (mFragmentTitleList.get(i).equals(name)) { 
       return true; 
      } 
     } 
     return false; 
    } 

    public int getTabPosition(String tabName) throws IndexOutOfBoundsException{ 
     for(int i = 0; i < mFragmentTitleList.size(); i++) { 
      if (mFragmentTitleList.get(i).equals(tabName)) { 
       return i; 
      } 
     } 
     throw new IndexOutOfBoundsException(); 
    } 

    @Override 
    public void setPrimaryItem(ViewGroup container, int position, Object object) { 
     Fragment fragment = (Fragment)object; 
     if (fragment != mCurrentPrimaryItem) { 
      if (mCurrentPrimaryItem != null) { 
       mCurrentPrimaryItem.setMenuVisibility(false); 
       mCurrentPrimaryItem.setUserVisibleHint(false); 
      } 
      if (fragment != null) { 
       fragment.setMenuVisibility(true); 
       fragment.setUserVisibleHint(true); 
      } 
      mCurrentPrimaryItem = fragment; 
     } 
    } 

    @Override 
    public void finishUpdate(ViewGroup container) { 
     if (mCurTransaction != null) { 
      mCurTransaction.commitAllowingStateLoss(); 
      mCurTransaction = null; 
      mFragmentManager.executePendingTransactions(); 
     } 

     ArrayList<Fragment> update = new ArrayList<Fragment>(); 
     for (int i=0, n=mFragments.size(); i < n; i++) { 
      Fragment f = mFragments.get(i); 
      if (f == null) continue; 
      int pos = getItemPosition(f); 
      while (update.size() <= pos) { 
       update.add(null); 
      } 
      update.set(pos, f); 
     } 
     mFragments = update; 
    } 


    @Override 
    public boolean isViewFromObject(View view, Object object) { 
     return ((Fragment)object).getView() == view; 
    } 

    @Override 
    public Parcelable saveState() { 
     Bundle state = null; 
     if (mSavedState.size() > 0) { 
      state = new Bundle(); 
      Fragment.SavedState[] fss = new Fragment.SavedState[mSavedState.size()]; 
      mSavedState.toArray(fss); 
      state.putParcelableArray("states", fss); 
     } 
     for (int i=0; i<mFragments.size(); i++) { 
      Fragment f = mFragments.get(i); 
      if (f != null && f.isAdded()) { 
       if (state == null) { 
        state = new Bundle(); 
       } 
       String key = "f" + i; 
       mFragmentManager.putFragment(state, key, f); 
      } 
     } 
     return state; 
    } 

    @Override 
    public void restoreState(Parcelable state, ClassLoader loader) { 
     if (state != null) { 
      Bundle bundle = (Bundle)state; 
      bundle.setClassLoader(loader); 
      Parcelable[] fss = bundle.getParcelableArray("states"); 
      mSavedState.clear(); 
      mFragments.clear(); 
      if (fss != null) { 
       for (int i=0; i<fss.length; i++) { 
        mSavedState.add((Fragment.SavedState)fss[i]); 
       } 
      } 
      Iterable<String> keys = bundle.keySet(); 
      for (String key: keys) { 
       if (key.startsWith("f")) { 
        int index = Integer.parseInt(key.substring(1)); 
        Fragment f = mFragmentManager.getFragment(bundle, key); 
        if (f != null) { 
         while (mFragments.size() <= index) { 
          mFragments.add(null); 
         } 
         f.setMenuVisibility(false); 
         mFragments.set(index, f); 
        } else { 
         Log.w(TAG, "Bad fragment at key " + key); 
        } 
       } 
      } 
     } 
    } 

    @Override 
    public int getItemPosition(Object object) { 
     if (mFragmentList.contains(object)) return mFragmentList.indexOf(object); 
     else return POSITION_NONE; 
    } 

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

    @Override 
    public CharSequence getPageTitle(int position) { 
     return mFragmentTitleList.get(position); 
    } 

} 

Selamlar!