रीसायकल दृश्य - java.lang.NullPointerException

Question

मैं अपवाद निम्न हो रही है, जबकि मैं रीसायकल दृश्य प्रदर्शित करने की कोशिश कर रहा हूँ:

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 

और मेरे एक्सएमएल यह है:

<?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> 

और मेरे जावा कोड

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(); 
      } 
     }); 
    } 
} 

मैं भी match_parent और wrap_contant के रूप में पुनरावृत्ति देखने के layout_height सेट करने का प्रयास कर रहा हूँ, लेकिन अभी भी मैं ही erro मिलती है: यह है आर

Answer 1

मुझे लगता है कि आप जावा कोड कड़ी में RecyclerView initialised चाहिए इस

//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); 

Answer 2

आप किसी भी लेआउट फ़ाइल जो यू जावा नियंत्रक (गतिविधि/टुकड़ा) से निपटा नहीं किया है में recyclerView घोषित करते हैं?

मैं दो टुकड़ों में दो रीसाइक्लिंग लेआउट घोषित करता हूं, मैं अपने जावा कोड में पहला पुनर्चक्रण संसाधित करता हूं, दूसरे के साथ निपटा नहीं है। जब मैं पुनर्नवीनीकरण हटाता हूं तो खंड 2-लेआउट-फ़ाइल में दृश्य घोषणा, यह शून्य सूचक समस्या हल हो गई।

Answer 3

एक्सएमएल से इस लाइन निकालें:

एंड्रॉयड: स्क्रॉलबार = "ऊर्ध्वाधर"

Answer 4

यहाँ कैसे मैं अंत में इस समस्या का समाधान है।

मैं RecyclerView घोषणा से android:scrollbars="vertical" हटाया:

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

Answer 5

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

बदलें

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