回收视图 - 显示java.lang.NullPointerException

我得到以下异常而我试图显示回收的观点：回收视图 - 显示java.lang.NullPointerException

java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.support.v7.widget.RecyclerView$LayoutManager.canScrollVertically()' on a null object reference 
at android.support.v7.widget.RecyclerView.computeVerticalScrollRange(RecyclerView.java:1216) 
    at android.view.View.onDrawScrollBars(View.java:13900) 
    at android.view.View.draw(View.java:16275) 
    at android.support.v7.widget.RecyclerView.draw(RecyclerView.java:2440) 
    at android.view.View.updateDisplayListIfDirty(View.java:15192) 
    at android.view.View.getDisplayList(View.java:15215) 
    at android.view.View.draw(View.java:15990) 
    at android.view.ViewGroup.drawChild(ViewGroup.java:3708) 
    at android.view.ViewGroup.dispatchDraw(ViewGroup.java:3502) 
    at android.view.View.draw(View.java:16272) 
    at android.view.View.updateDisplayListIfDirty(View.java:15192) 
    at android.view.View.getDisplayList(View.java:15215) 
    at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3692) 
    at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3671) 
    at android.view.View.updateDisplayListIfDirty(View.java:15152) 
    at android.view.View.getDisplayList(View.java:15215) 
    at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3692) 
    at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3671) 
    at android.view.View.updateDisplayListIfDirty(View.java:15152) 
    at android.view.View.getDisplayList(View.java:15215) 
    at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:362) 
    at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3671) 
    at android.view.View.updateDisplayListIfDirty(View.java:15152) 
    at android.view.View.getDisplayList(View.java:15215) 
    at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3692) 
    at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3671) 
    at android.view.View.updateDisplayListIfDirty(View.java:15152) 
    at android.view.View.getDisplayList(View.java:15215) 
    at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3692) 
    at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3671) 
    at android.view.View.updateDisplayListIfDirty(View.java:15152) 
    at android.view.View.getDisplayList(View.java:15215) 
    at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3692) 
    at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3671) 
    at android.view.View.updateDisplayListIfDirty(View.java:15152) 
    at android.view.View.getDisplayList(View.java:15215) 
    at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3692) 
    at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3671) 
    at android.view.View.updateDisplayListIfDirty(View.java:15152) 
    at android.view.View.getDisplayList(View.java:15215) 
    at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3692) 
    at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3671) 
    at android.view.View.updateDisplayListIfDirty(View.java:15152) 
    at android.view.View.getDisplayList(View.java:15215) 
    at android.view.ViewGroup.recreateChildDisplayList(ViewGroup.java:3692) 
    at android.view.ViewGroup.dispatchGetDisplayList(ViewGroup.java:3671) 
    at android.view.View.updateDisplayListIfDirty(View.java:15152) 
    at android.view.View.getDisplayList(View.java:15215) 
    at android.view.ThreadedRenderer.updateViewTreeDisplayList(ThreadedRenderer.java:307) 
    at android.view.ThreadedRenderer.updateRootDisplayList(ThreadedRenderer.java:313) 
    at android.view.ThreadedRenderer.draw(ThreadedRenderer.java:352) 
    at android.view.ViewRootImpl.draw(ViewRootImpl.java:2811) 
    at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2634) 
    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2222) 
    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1230) 
    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6726) 
    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:777) 
    at android.view.Choreographer.doCallbacks(Choreographer.java:590) 
    at android.view.Choreograph

和我的XML是这样的：

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    style="@style/global_screen_linear_layout" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:orientation="vertical" > 

    <LinearLayout 
     android:id="@+id/lilAdvancedSearchParent" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:background="@color/gray_general" 
     android:gravity="center_vertical" 
     android:orientation="horizontal" 
     android:padding="10dp" > 

     <LinearLayout 
      android:id="@+id/lilAdvancedSearch" 
      android:layout_width="0dp" 
      android:layout_height="match_parent" 
      android:layout_weight="6" 
      android:gravity="center_vertical" > 

      <ImageView 
       android:id="@+id/imageView2" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:src="@drawable/arrow_white" /> 

      <TextView 
       android:id="@+id/txvAvencedSearch" 
       android:layout_width="0dp" 
       android:layout_height="wrap_content" 
       android:layout_marginRight="10dp" 
       android:layout_weight="4.5" 
       android:text="@string/global_fragment_advenced_search" 
       android:textColor="@color/white" 
       android:textSize="@dimen/global_screen_layout_text_view_advenced_search" 
       android:textStyle="bold" /> 
     </LinearLayout> 

     <EditText 
      android:id="@+id/edtSearch" 
      android:layout_width="0dp" 
      android:layout_height="wrap_content" 
      android:layout_weight="9" 
      android:drawableLeft="@drawable/navigation_search" 
      android:ems="10" 
      android:imeOptions="actionSearch" 
      android:inputType="text" 
      android:textColor="@color/white" 
      android:textColorHint="@color/white" 
      android:textSize="15sp" > 

      <requestFocus /> 
     </EditText> 
    </LinearLayout> 

    <android.support.v7.widget.RecyclerView 
       android:id="@+id/my_recycler_view" 
       android:layout_width="match_parent" 
       android:layout_height="800dp" 
       android:scrollbars="vertical" > 
      </android.support.v7.widget.RecyclerView> 

</LinearLayout>

和我的Java代码是这样的：

public class TendersFragment extends BaseFragment{ 



    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
      Bundle savedInstanceState) { 
     View v = inflater.inflate(R.layout.global_screen_layout, container, false); 
     initUI(v); 
     initListeners(); 
     setEditSearchHint(getString(R.string.tenders_fragment_search_tenders)); 
     setAdvancedSearchBackground(getResources().getColor(R.color.green_general)); 
     return v; 
    } 

    @Override 
    protected void initUI(View view) { 
     lsvTendersJobsMessages = (ListView) view.findViewById(R.id.lsvGlobal); 

     mRecyclerView = (RecyclerView) view.findViewById(R.id.my_recycler_view); 
     setAdapterForListview(lsvTendersJobsMessages); 

     edtSearch = (EditText) view.findViewById(R.id.edtSearch); 
     txvAdvencedSearch = (TextView) view.findViewById(R.id.txvAvencedSearch); 
     lilAdvancedSearch = (LinearLayout) view.findViewById(R.id.lilAdvancedSearch);  
     lilAdvancedSearchParent = (LinearLayout) view.findViewById(R.id.lilAdvancedSearchParent); 


    } 

    @Override 
    protected void setAdapterForListview(ListView lsv) { 
     mRecyclerView.setHasFixedSize(true); 
     mLinearLayoutManager = new LinearLayoutManager(getActivity()); 
     mLinearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);  
     mRecyclerView.setLayoutManager(mLinearLayoutManager); 

     ArrayList<ItemType> arlItems = new ArrayList<ItemType>(); 
     arlItems.add(ItemType.MAIN_ITEM); 
     arlItems.add(ItemType.MAIN_ITEM); 
     arlItems.add(ItemType.MAIN_ITEM); 
     arlItems.add(ItemType.MAIN_ITEM); 
     arlItems.add(ItemType.MAIN_ITEM); 
     arlItems.add(ItemType.MAIN_ITEM); 
     arlItems.add(ItemType.MAIN_ITEM); 
     arlItems.add(ItemType.MAIN_ITEM); 
     arlItems.add(ItemType.MAIN_ITEM); 

     // specify an adapter (see also next example) 
     mainItemAdapter = new MainItemAdapter(arlItems, getActivity()); 
     mRecyclerView.setAdapter(mainItemAdapter); 
    } 

    @Override 
    protected void onServiceConnected() { 
     // TODO Auto-generated method stub 

    } 


    protected void initListeners() { 

     final AdvancedSearchFragment advancedSearchFragment = new AdvancedSearchFragment(); 
     Bundle bundle = new Bundle();  
     bundle.putInt(FragmentConst.BUNDLE_KEY_INT_WHICH_FRAGMENT,FragmentConst.TENDERS_ID);  
     advancedSearchFragment.setArguments(bundle); 
     lilAdvancedSearch.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View v) {     
        getActivity().getSupportFragmentManager().beginTransaction() 
        .add(android.R.id.content,advancedSearchFragment).addToBackStack(null) 
        .commit(); 
      } 
     }); 
    } 
}

我也尝试设置循环视图match_parent和wrap_contant的layout_height但我仍然会得到相同的埃罗[R

来源

2015-05-17 gil cohen

发布您的代码，请 –

发布您的代码，以你在哪里得到这个错误。 – dora

你的java代码也 –

我想你一定在Java代码中的链接初始化RecyclerView此

//1. get a reference to recyclerView 
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerView); 

//2. set layoutManger 
recyclerView.setLayoutManager(new LinearLayoutManager(this)); 

// 3. create an adapter 
MyAdapter mAdapter = new MyAdapter(itemsData); 

// 4. set adapter 
recyclerView.setAdapter(mAdapter);

来源

2015-05-17 08:57:24

你的代码与我的有什么不同？ –

mRecyclerView.setHasFixedSize（true）; mLLinearLayoutManager = new LinearLayoutManager（getActivity（））; mLLayoutManager.setOrientation（LinearLayoutManager.VERTICAL）; mLinearLayoutManager.setOrientation（LinearLayoutManager.VERTICAL）; mRecyclerView.setLayoutManager（mLinearLayoutManager）; 将此代码放入'init'方法 –

仍然，我得到相同的异常 –

你的u没有在Java控制器（活动/片段）处理的任何布局文件中声明recyclerView？

我在两个片段中声明了两个回收器布局，我在我的java代码中处理第一个回收器，没有处理第二个回收器。在删除fragment2-layout-file中的recyclerView声明后，它解决了空指针问题。

来源

2015-06-13 14:21:47

从XML删除此行：

的android：滚动条= “垂直”

来源

2015-10-01 18:41:21 FlipNovid

tx您的答案帮助我 –

下面是我终于解决了这个问题。

我删除android:scrollbars="vertical"从RecyclerView声明：

<android.support.v7.widget.RecyclerView 
    android:id="@+id/task_recycler_view" 
    android:scrollbars="vertical" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent"/>

来源

2015-11-27 20:37:31 windflyer

嗯，这确实为我解决了这个问题，但是我在另一个视图中有这样的布局，但是在加载该视图时我没有收到错误： \ – Phil

更换

mLinearLayoutManager = new LinearLayoutManager(getActivity()); 
mLinearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL); 
mRecyclerView.setLayoutManager(mLinearLayoutManager);

与

final LinearLayoutManager mLayoutManager= new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, true);    
mRecyclerView.setLayoutManager(mLayoutManager);

来源

2016-10-14 08:42:29

回收视图 - 显示java.lang.NullPointerException

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