ViewPagerの範囲外の配列

Question

ViewPagerクラスの範囲外の配列を取得しようとしていますが、その理由はわかりません。

すぐにビューのページャをスワイプするときに発生するようで、アイテムを保持している内部配列が空であるように、それはここでは、インデックス0

をつかむしようとしているので、それはスタックトレースが

java.lang.IndexOutOfBoundsException: Invalid index 0, size is 0 
    at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255) 
    at java.util.ArrayList.get(ArrayList.java:308) 
    at android.support.v4.view.ViewPager.performDrag(ViewPager.java:2343) 
    at android.support.v4.view.ViewPager.onTouchEvent(ViewPager.java:2262) 
    at android.view.View.dispatchTouchEvent(View.java:8471) 
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2399) 
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2092) 
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2405) 
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2106) 
    at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2369) 
    at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1719) 
    at android.app.Activity.dispatchTouchEvent(Activity.java:2742) 
    at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2330) 
    at android.view.View.dispatchPointerEvent(View.java:8666) 
    at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:4123) 
    at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:3989) 
    at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3544) 
    at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3597) 
    at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3563) 
    at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3680) 
    at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3571) 
    at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3737) 
    at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3544) 
    at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3597) 
    at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3563) 
    at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3571) 
    at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3544) 
    at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:5807) 
    at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:5781) 
    at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:5752) 
    at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:5897) 
    at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:185) 
    at android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(Native Method) 
at android.view.InputEventReceiver.consumeBatchedInputEvents(InputEventReceiver.ja 

で見えます

ここでコードは、ビューページを設定し、アダプタを設定するコードです。この場合、isTabletパスに従います。ここで

private void initializePaging() { 

    if (resources.getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) { 
     menuGridSize = 3; 
    } 
    else { 
     menuGridSize = 4; 
    } 

    if (mMenus != null) { 
     if (Utility.isTabletDevice(getActivity())) { 
      int count = mMenus.size()/menuGridSize; 
      int extras = mMenus.size() % menuGridSize; 

      int activatedIndicator = 0; 
      if (pageIndicators != null) { 
       for (int i = 0; i < pageIndicators.size(); i++) { 
        if (pageIndicators.get(i).isActivated()) { 
         activatedIndicator = i; 
         break; 
        } 
       } 
      } 

      pageIndicatorLayout.removeAllViews(); 
      pageIndicators = new ArrayList<>(); 
      for (int i = 0; i < count; i++) { 
       ImageView temp = new ImageView(context); 
       temp.setPadding(10, 10, 10, 10); 
       temp.setImageDrawable(mTheme.pageIndicatorSelector(context)); 
       pageIndicatorLayout.addView(temp); 
       pageIndicators.add(temp); 
      } 

      if (extras != 0) { 
       ImageView temp = new ImageView(context); 
       temp.setPadding(10, 10, 10, 10); 
       temp.setImageDrawable(mTheme.pageIndicatorSelector(context)); 
       pageIndicatorLayout.addView(temp); 
       pageIndicators.add(temp); 
      } 
      pageIndicators.get(activatedIndicator).setActivated(true); 

      if (pageIndicators.size() <= 1) { 
       pageIndicatorLayout.setVisibility(View.GONE); 
      } 

      if (adapter == null) { 
       adapter = new MainMenuPagerAdapter(getFragmentManager(), mMenus, menuGridSize, changeFragmentListener); 
      } 
      else { 
       adapter.setGridSize(menuGridSize); 
      } 

      pager.setAdapter(adapter); 
      pager.setOnPageChangeListener(new OnPageChangeListener() { 

       public void onPageScrollStateChanged(int arg0) { 

       } 

       public void onPageScrolled(int arg0, float arg1, int arg2) { 

       } 

       public void onPageSelected(int arg0) { 

        for (int i = 0; i < pageIndicators.size(); i++) { 
         if (i == arg0) { 
          pageIndicators.get(i).setActivated(true); 
         } 
         else { 
          pageIndicators.get(i).setActivated(false); 
         } 
        } 
       } 
      }); 

      adapter.notifyDataSetChanged(); 
      progress.setVisibility(View.GONE); 
      pager.setVisibility(View.VISIBLE); 
     } 
     else { 
      menuList.setAdapter(new MainMenuAdapter(getActivity(), mMenus)); 
      progress.setVisibility(View.GONE); 
      menuList.setVisibility(View.VISIBLE); 
     } 

     view.invalidate(); 
    } 
} 

は、この問題はおそらく、ソースファイルによって引き起こされるアダプタのコード

public class MainMenuPagerAdapter extends FragmentStatePagerAdapter { 

public static final String TAG = "MainMenuPagerAdapter"; 

private List<GenericMenu> menus = new ArrayList<>(); 
private int gridSize; 
private ChangeFragmentListener changeFragmentListener; 

public MainMenuPagerAdapter(FragmentManager fragmentManager, List<GenericMenu> menus, int gridSize, final ChangeFragmentListener changeFragmentListener) { 

    super(fragmentManager); 
    this.menus = menus; 
    this.gridSize = gridSize; 
    this.changeFragmentListener = changeFragmentListener; 
} 

public void setGridSize(int gridSize) { 

    this.gridSize = gridSize; 
} 

@Override 
public Fragment getItem(int position) { 

    int subListStart = position * gridSize; 
    int subListEnd = position * gridSize + gridSize; 

    if (subListEnd >= menus.size()) { 
     subListEnd = menus.size(); 
    } 

    // find the menus for this page 
    ArrayList<GenericMenu> subList = new ArrayList<GenericMenu>(); 
    subList.addAll(menus.subList(subListStart, subListEnd)); 

    Bundle bundle = new Bundle(); 
    bundle.putParcelableArrayList("menus", subList); 
    bundle.putInt("columns", gridSize); 
    MainMenuPageFragment fragment = new MainMenuPageFragment(); 
    fragment.setArguments(bundle); 
    fragment.setChangeFragmentListener(new ChangeFragmentListener() { 

     public void changeFragment(BaseIceFragment fragment, String titleText, String image, float size) { 

      if (changeFragmentListener != null) { 
       changeFragmentListener.changeFragment(fragment, titleText, image, size); 
      } 
     } 
    }); 

    return fragment; 
} 

@Override 
public int getCount() { 

    int count = menus.size()/gridSize; 
    count += menus.size() % gridSize > 0 ? 1 : 0; 

    return count; 
} 

@Override 
public int getItemPosition(Object object) { 

    return POSITION_NONE; 
} 

@Override 
public Parcelable saveState() { 

    // Do nothing 
    return null; 
} 
} 

Answer 1

です。 ViewPagerのsetAdaper（）mItemsはnullに設定されています。 ViewPagerをドラッグしてsetAdapterを呼び出すと、この問題が発生します。 performDrag（）メソッドmItems.get（0）がサイズチェックを追加しないことがわかります。

SOLUTION：使用notifyDataChangedではなくsetAdapterのデータをリフレッシュする：

if(mAdapter == null){ 
    mAdapter = new CarInfoViewPagerAdapter(views); 
} else { 
    mAdapter.setViews(views); 
} 
if(mViewPager.getAdapter() == null){ 
    mViewPager.setAdapter(mAdapter); 
} else { 
    mAdapter.notifyDataSetChanged(); 
} 

• をあなたがコードを提供しなかったので、私は名前だけ作ら - mItems、mAdapterとmViewPagerを、私は確信していますあなたは関係することができます。お役に立てれば。