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Vue de recyclage - exception Java.lang.NullPointerException

Je reçois une exception suivante pendant que j'essaie d'afficher la vue de recyclage:

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

et mon xml est ceci:

<?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>

et mon code Java est le suivant:

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();
            }
        });
    }
}

je tente également de définir la hauteur de mise en page de la vue de recyclage comme match_parent et wrap_contant, mais j'obtiens toujours la même erreur.

androidnullpointerexceptionandroid-recyclerview
11
gil cohen

Voici comment j'ai finalement résolu ce problème.

J'ai supprimé Android:scrollbars="vertical" de la déclaration RecyclerView:

<Android.support.v7.widget.RecyclerView
    Android:id="@+id/task_recycler_view"
    Android:scrollbars="vertical"
    Android:layout_width="match_parent"
    Android:layout_height="match_parent"/>
16
windflyer

Supprimez cette ligne du fichier XML: 

Android: barres de défilement = "vertical"

9
FlipNovid

Je pense que vous devez initialiser RecyclerView en code Java lier cette

//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);
3
N J

Déclarez-vous recyclerView dans n’importe quel fichier d’agencement qui n’a pas été traité dans le contrôleur Java (Activity/Fragment)?

Je déclare deux schémas de recycleur en deux fragments, je traite le 1er recycleur dans mes codes Java, je n’ai pas traité le second. Après avoir supprimé la déclaration recyclerView du fichier fragment2-layout-file, le problème du pointeur null a été résolu.

2
Roy Guanyu

Remplacer 

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

avec 

final LinearLayoutManager mLayoutManager= new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, true);            
mRecyclerView.setLayoutManager(mLayoutManager);
0
sushant gosavi