Gaveta de navegação Reciclador Exibir ponteiro nulo Exceção

Question

Feb 08, 2016, 07:56 PM

android-recyclerview recycler-adapter android

Gaveta de navegação Reciclador Exibir ponteiro nulo Exceção

Estou trabalhando com o recycleView de acordo com o tutorial de design de material, fiz tudo de acordo, mas meu logCat diz:

E/AndroidRuntime: FATAL EXCEPTION: main Process: com.portal.college.myapplication, PID: 6541 java.lang.NullPointerException 
 at android.support.v7.widget.RecyclerView$Adapter.createViewHolder(RecyclerView.java:5229) 
 at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4453)
 at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4363)
 at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:1961)
 at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1370)
 at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1333)
 at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:562)
 at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:2900)
 at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3071)
 at android.view.View.layout(View.java:14817)
 at android.view.ViewGroup.layout(ViewGroup.java:4631)
 at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1055)
 at android.view.View.layout(View.java:14817)
 at android.view.ViewGroup.layout(ViewGroup.java:4631)
 at android.support.v4.widget.DrawerLayout.onLayout(DrawerLayout.java:1067)
 at android.view.View.layout(View.java:14817)
 at android.view.ViewGroup.layout(ViewGroup.java:4631)
 at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
 at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
 at android.view.View.layout(View.java:14817)
 at android.view.ViewGroup.layout(ViewGroup.java:4631)
 at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
 at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525)
 at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
 at android.view.View.layout(View.java:14817)
 at android.view.ViewGroup.layout(ViewGroup.java:4631)
 at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
 at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
 at android.view.View.layout(View.java:14817)
 at android.view.ViewGroup.layout(ViewGroup.java:4631)
 at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671)
 at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525)
 at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
 at android.view.View.layout(View.java:14817)
 at android.view.ViewGroup.layout(ViewGroup.java:4631)
 at android.widget.FrameLayout.layoutChildren(FrameLayout.java:453)
 at android.widget.FrameLayout.onLayout(FrameLayout.java:388)
 at android.view.View.layout(View.java:14817)
 at android.view.ViewGroup.layout(ViewGroup.java:4631)
 at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1983)
 at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1740)
 at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:996)
 at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5600)
 at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)
 at android.view.Choreographer.doCallbacks(Choreographer.java:574)
 at android.view.Choreographer.doFrame(Choreographer.java:544)
 at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747)
 at android.os.Handler.handleCallback(Handler.java:733)
 at android.os.Handler.dispatchMessage(Handler.java:95)
 at android.os.Looper.loop(Looper.java:136)
 at android.app.ActivityThread.main(ActivityThread.java:5001)
 at java.lang.reflect.Method.invokeNative(Native Method)
 at java.lang.reflect.Method.invoke(Method.java:515)
 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
 at dalvik.system.NativeStart.main(Native Method)

main_layout.xml

 <?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:elevation="7dp">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <include
            android:id="@+id/app_bar"
            layout="@layout/app_bar_main"  />
   </LinearLayout>
    <fragment
        android:id="@+id/fragment_navigation_drawer"
        android:layout_width="280dp"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        app:layout="@layout/fragment_navigation_drawer"
        android:name="com.portal.college.myapplication.NavigationDrawerFragment"
        tools:layout="@layout/fragment_navigation_drawer"
        />   
</android.support.v4.widget.DrawerLayout>

O arquivo xml do layout do fragmento é: fragment_navigation_drawer.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#8c8c8c"
tools:context="com.portal.college.myapplication.NavigationDrawerFragment">

<include
    android:id="@+id/nav_head"
    layout="@layout/nav_header_main"  />
<android.support.v7.widget.RecyclerView
    android:id="@+id/drawerList"
    android:layout_width="match_parent"

    android:layout_height="wrap_content"
    >
</android.support.v7.widget.RecyclerView>

</RelativeLayout>

Agora MainActivity.java

 package com.portal.college.myapplication;

import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {
private RecyclerView recyclerView;
    private Toolbar toolbar;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
getSupportActionBar().setDisplayShowHomeEnabled(true);
        NavigationDrawerFragment drawerFragment = (NavigationDrawerFragment)
                getSupportFragmentManager().findFragmentById(R.id.fragment_navigation_drawer);

        drawerFragment.setUp((DrawerLayout) findViewById(R.id.drawer_layout),toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });

    }

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if(id == R.id.action_settings) {
            return true;
        }
        if(id == R.id.search) {
             startActivity(new Intent(this, SearchActivity.class));
        }

        return super.onOptionsItemSelected(item);

    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }
}

NavigationDrawerFragment.java

package com.portal.college.myapplication;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.support.v7.widget.Toolbar;

import java.util.ArrayList;
import java.util.List;

    public class NavigationDrawerFragment extends Fragment {
        private ActionBarDrawerToggle mDrawerToggle;
        private DrawerLayout mDrawerLayout;
        private RecyclerView recyclerView;
    private VivzAdapter adapter;
        public NavigationDrawerFragment() {
            // Required empty public constructor
        }


        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            // Inflate the layout for this fragment
            View layout = inflater.inflate(R.layout.fragment_navigation_drawer,container,false);
            recyclerView = (RecyclerView) layout.findViewById(R.id.drawerList);
            adapter = new VivzAdapter(getActivity(),getData());

            recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
            recyclerView.setAdapter(adapter);
            return layout;
        }
        public static List<Information> getData(){
            List<Information> data = new ArrayList<>();
            int icons[] = {
                    R.drawable.ic_menu_camera,
                    R.drawable.ic_menu_gallery,
                    R.drawable.ic_menu_manage,
                    R.drawable.ic_menu_send};
            String[] title = {"Camera","Gallery","Settings","Send"};
            for(int i=0;i<title.length && i<icons.length;i++){
                Information current = new Information();
                current.iconId = icons[i];
                current.title = title[i];
                data.add(current);
            }
            return data;

        }


        public void setUp(DrawerLayout drawerLayout,Toolbar toolbar) {
            mDrawerLayout = drawerLayout;
            mDrawerToggle = new ActionBarDrawerToggle(getActivity(), drawerLayout, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close){
                public void onDrawerOpened(View drawerView){
                    super.onDrawerOpened(drawerView);

                    }
                public void onDrawerClosed(View drawerView){
                    super.onDrawerClosed(drawerView);

                }

            };
            mDrawerLayout.setDrawerListener(mDrawerToggle);
            mDrawerLayout.post(new Runnable() {

                @Override
                public void run() {
                    mDrawerToggle.syncState();
                }
            });
          /*  containerView = getActivity().findViewById(fragment_id);
            mDrawerLayout=drawerLayout;
            mDrawerToggle = new ActionBarDrawerToggle(getActivity(), drawerLayout, toolbar, R.string.open_drawer,R.string.close_drawer){
                @SuppressLint("NewApi")
                public void onDrawerOpened(View drawerView){
                    super.onDrawerOpened(drawerView);
                     if(!mUserLearnedDrawer){
                         mUserLearnedDrawer = false;
                         saveToPreferences(getActivity(),KEY_USER_LEARNED_DRAWER, mUserLearnedDrawer+"");
                     }
                     getActivity().invalidateOptionsMenu();
                     */
                }

    }

A classe do adaptador é VivzAdapter.cjava

    package com.portal.college.myapplication;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import java.util.Collections;
import java.util.List;

/**
 * Created by admin on 08-Feb-16.
 */
public class VivzAdapter extends RecyclerView.Adapter<VivzAdapter.MyViewHolder>{
    private final LayoutInflater inflater;
    List<Information> data = Collections.emptyList();

    public VivzAdapter(Context context,List<Information> data){
    inflater=LayoutInflater.from(context);
        this.data=data;
}
    @Override
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = inflater.inflate(R.layout.custom_row,parent,false);
        MyViewHolder holder = new MyViewHolder(view);
        return null;
    }


    @Override
    public void onBindViewHolder(MyViewHolder holder, int position) {
Information current = data.get(position);
        holder.title.setText(current.title);
        holder.id.setImageResource(current.iconId);
    }

    @Override
    public int getItemCount() {

            return data.size();

    }
class MyViewHolder extends RecyclerView.ViewHolder{
    TextView title;
    ImageView id;

    public MyViewHolder(View itemView) {
        super(itemView);
        title = (TextView) itemView.findViewById(R.id.listText);
        id = (ImageView) itemView.findViewById(R.id.listIcon);
    }
}
}

A lista Item class é Information.java

  package com.portal.college.myapplication;

/**
 * Created by admin on 08-Feb-16.
 */
public class Information {
    int iconId;
    String title;
}

O layout da linha da lista é custom_row.xml

    <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:layout_height="match_parent">
<ImageView
    android:id="@+id/listIcon"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/ic_menu_camera"/>
    <TextView
        android:id="@+id/listText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Camera"
        />
         </LinearLayout>

Passei pela maior parte da solução no stackoverflow que trata do mesmo problema, mas falhei aqui.

Uma coisa que notei que emVivzAdapter.java, o nome da funçãogetItemCount() que está recebendo os dadosCount devolver odata.size(), quando eu mudo para retornar0 funciona por semrecyclerView, mas quando retornado comdata.size(), dáNullPointerException.

Espero ter explicado tudo em detalhes.

Qualquer conselho seria muito apreciado