CODEWITHSUNDEEP
android
Han Tran
Han Tran

Reputation: 9

Cannot set Custom Adapter to ListView

I try to set a Customer Adapter to ListView but always receive NullException. This is my Adapter:

public class MovieAdapter extends BaseAdapter{
    private Context mContext;
    // Add mVar of resource, an array for example
    private List<Movie> mMovies;



    // Automatically create constructor for all mVar


    public MovieAdapter(Context context, List<Movie> movies) {
        mContext = context;
        mMovies = movies;
    }

    public MovieAdapter(Callback<NowPlaying> callback, List<Movie> movies) {
    }


    // Automatically create required methods and override them with mVar
    @Override
    public int getCount() {
        return mMovies.size();
    }

    @Override
    public Object getItem(int position) {
        return mMovies.get(position);
    }

    @Override
    public long getItemId(int position) {
        return 0; // Use to easier get position reference
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;

        if (convertView == null) {
            // If the ListView is brand new

            convertView = LayoutInflater.from(mContext).inflate(R.layout.list_movie_item,
                    parent, false);
            // Get layout from the context and inflate it the daily_list_item.

            // Use ViewHolder to create smooth scrolling list

            holder = new ViewHolder(convertView);

            // Set the tag for reuse the View
            convertView.setTag(holder);

        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        //Set content to holderVar from get
        //Create the ModelClass object as an element in the array
        // Remember even the Image need to be set (different from MainAct)
        Movie movie = mMovies.get(position);
        holder.mTvLeftTitle.setText(movie.getTitle());
        holder.mTvLeftOverview.setText(movie.getOverview());
//        holder.mTvLeftCast.setText(movie.getCast());
        Glide.with(mContext)
                .load(movie.getPosterPath())
                .into(holder.mImgLeftPoster);

        holder.mTvRightTitle.setText(movie.getTitle());
        holder.mTvRightOverview.setText(movie.getOverview());
//        holder.mTvLeftCast.setText(movie.getCast());
        Glide.with(mContext)
                .load(movie.getPosterPath())
                .into(holder.mImgRightPoster);


        return convertView;
    }

    // Create class ViewHolder with Widget as variable based on Model class
    static class ViewHolder {
        // Using ButterKnife to create and hook Widget (remember the Image, too)
        @BindView(R.id.rlLeftLayout)
        RelativeLayout mRlLeftLayout;
        @BindView(R.id.tvLeftTitle)
        TextView mTvLeftTitle;
        @BindView(R.id.tvLeftOverview)
                TextView mTvLeftOverview;
        @BindView(R.id.tvLeftCast)
        TextView mTvLeftCast;
        @BindView(R.id.imgLeftPoster)
        ImageView mImgLeftPoster;

        @BindView(R.id.rlRightLayout)
        RelativeLayout mRlRightLayout;
        @BindView(R.id.tvRightTitle)
        TextView mTvRightTitle;
        @BindView(R.id.tvRightOverview)
        TextView mTvRightOverview;
        @BindView(R.id.tvRightCast)
        TextView mTvRightCast;
        @BindView(R.id.imgRightPoster)
        ImageView mImgRightPoster;


        ViewHolder(View view) {
            ButterKnife.bind(this, view);
        }
    }
}

This is my Activity:

public class MainActivity extends AppCompatActivity {
    private static final String TAG = MainActivity.class.getSimpleName();
    MovieAdapter mAdapter;
    List<Movie> mMovies = new ArrayList<Movie>();

    private NowPlaying mNowPlaying;

    @BindView(android.R.id.list)
    ListView mListView;
    @BindView(android.R.id.empty)
    TextView mEmptyView;
    private MovieApi mMovieApi;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);

//        final MovieAdapter adapter = new MovieAdapter(this, mMovies);
//
        mMovieApi = RetrofitUtils.get(getString(R.string.api_key)).create(MovieApi.class);
        mMovieApi.getNowPlaying().enqueue(new Callback<NowPlaying>() {

            @Override
            public void onResponse(Call<NowPlaying> call, Response<NowPlaying> response) {

                Log.d("Response", String.valueOf(response.isSuccessful()));
                mMovies = response.body().getMovies();
                mAdapter = new MovieAdapter(this, mMovies);
                mListView.setAdapter(mAdapter);
                mListView.setEmptyView(mEmptyView);



            }

            @Override
            public void onFailure(Call<NowPlaying> call, Throwable t) {
                Log.e("Error", t.getMessage());
                Toast.makeText(MainActivity.this, "OK", Toast.LENGTH_SHORT).show();



            }
        });



    }
}

My Stack Trace:

10-15 23:04:19.480 12537-12537/com.example.rubit1359.bigcornbox E/AndroidRuntime: FATAL EXCEPTION: main
                                                                                  Process: com.example.rubit1359.bigcornbox, PID: 12363
                                                                                  java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter(android.widget.ListAdapter)' on a null object reference
                                                                                      at com.example.rubit1359.bigcornbox.ui.MainActivity$1.onResponse(MainActivity.java:57)
                                                                                      at retrofit2.ExecutorCallAdapterFactory$ExecutorCallbackCall$1$1.run(ExecutorCallAdapterFactory.java:68)
                                                                                      at android.os.Handler.handleCallback(Handler.java:815)
                                                                                      at android.os.Handler.dispatchMessage(Handler.java:104)
                                                                                      at android.os.Looper.loop(Looper.java:194)
                                                                                      at android.app.ActivityThread.main(ActivityThread.java:5637)
                                                                                      at java.lang.reflect.Method.invoke(Native Method)
                                                                                      at java.lang.reflect.Method.invoke(Method.java:372)
                                                                                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:960)
                                                                                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

I have debugged the app to make sure that the mMovies ListView are filled. However I cannot set the Adapter. Anyone can help me spotting the error. Thank you.

UPDATE XML

XML activity

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/darkness"
    tools:context="com.example.rubit1359.bigcornbox.ui.MainActivity">

    <ListView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:id="@+id/ListView"
        android:layout_alignParentStart="true"
        android:layout_alignParentLeft="true"/>

    <TextView
        android:text="There is no data to display"
        android:textStyle="bold"
        android:textSize="20sp"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:textColor="@color/colorWhite"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/EmptyView"
        />

</RelativeLayout>

Adapter xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                xmlns:app="http://schemas.android.com/apk/res-auto"
                xmlns:tools="http://schemas.android.com/tools"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="@color/darkness">


    <RelativeLayout
        android:id="@+id/rlLeftLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:background="@color/skypeGray">


        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignBottom="@+id/imgLeftScoreBackground"
            android:layout_alignTop="@+id/imgLeftPoster"
            android:layout_toEndOf="@+id/imgLeftScoreBackground"
            android:layout_toRightOf="@+id/imgLeftScoreBackground"
            android:gravity="center_vertical"
            android:orientation="vertical"
            android:padding="16dp">

            <TextView
                android:id="@+id/tvLeftTitle"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:lineSpacingExtra="5dp"
                android:text="Captain America: Civil War"
                android:textAlignment="viewEnd"
                android:textColor="@color/redmilk"
                android:textSize="15sp"
                android:textStyle="bold"/>

            <TextView
                android:id="@+id/tvLeftOverview"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="15dp"
                android:ellipsize="end"
                android:lineSpacingExtra="5dp"
                android:maxLines="5"
                android:text="Following the events of Age of Ultron, the collective goverments of the world pass an act designed to regulate all superhuman activity. This polarizes opinion amongst the Avengers, causing two factions to side..."
                android:textAlignment="viewEnd"
                android:textColor="@color/colorWhite"
                android:textSize="12sp"/>

            <TextView
                android:id="@+id/tvLeftCast"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="20dp"
                android:text="Chris Evans, Robert Downey Jr."
                android:textAlignment="viewEnd"
                android:textColor="@color/colorWhite"
                android:textSize="12sp"
                android:textStyle="bold|italic"/>
        </LinearLayout>

        <ImageView
            android:id="@+id/imgLeftPoster"
            android:layout_width="120dp"
            android:layout_height="180dp"
            android:layout_alignParentLeft="true"
            android:layout_alignParentStart="true"
            android:layout_alignParentTop="true"
            app:srcCompat="@drawable/poster"/>

        <ImageView
            android:id="@+id/imgLeftScoreBackground"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/imgLeftPoster"
            android:layout_marginTop="3dp"
            app:srcCompat="@drawable/background"/>

    </RelativeLayout>

    <RelativeLayout
        android:id="@+id/rlRightLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentEnd="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:background="@color/skypeGray">

        <ImageView
            android:id="@+id/imgRightPoster"
            android:layout_width="120dp"
            android:layout_height="180dp"
            android:layout_alignParentEnd="true"
            android:layout_alignParentRight="true"
            android:layout_alignParentTop="true"
            app:srcCompat="@drawable/poster"/>

        <ImageView
            android:id="@+id/imgRightScoreBackground"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentEnd="true"
            android:layout_alignParentRight="true"
            android:layout_below="@+id/imgRightPoster"
            android:layout_marginTop="3dp"
            app:srcCompat="@drawable/background_right"/>


        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignBottom="@+id/imgRightScoreBackground"
            android:layout_alignTop="@+id/imgRightPoster"
            android:layout_toLeftOf="@+id/imgRightScoreBackground"
            android:layout_toStartOf="@+id/imgRightScoreBackground"
            android:gravity="center_vertical"
            android:orientation="vertical"
            android:padding="16dp">

            <TextView
                android:id="@+id/tvRightTitle"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:lineSpacingExtra="5dp"
                android:text="Captain America: Civil War"
                android:textAlignment="viewStart"
                android:textColor="@color/redmilk"
                android:textSize="15sp"
                android:textStyle="bold"/>

            <TextView
                android:id="@+id/tvRightOverview"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="15dp"
                android:ellipsize="end"
                android:lineSpacingExtra="5dp"
                android:maxLines="5"
                android:text="Following the events of Age of Ultron, the collective goverments of the world pass an act designed to regulate all superhuman activity. This polarizes opinion amongst the Avengers, causing two factions to side..."
                android:textAlignment="viewStart"
                android:textColor="@color/colorWhite"
                android:textSize="12sp"/>

            <TextView
                android:id="@+id/tvRightCast"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="20dp"
                android:text="Chris Evans, Robert Downey Jr."
                android:textAlignment="viewStart"
                android:textColor="@color/colorWhite"
                android:textSize="12sp"
                android:textStyle="bold|italic"/>
        </LinearLayout>


    </RelativeLayout>
</RelativeLayout>

Upvotes: 0

Views: 230

Answers (2)

Nongthonbam Tonthoi
Nongthonbam Tonthoi

Reputation: 12953

You are getting a wrong id: Change these lines:

@BindView(android.R.id.list)
ListView mListView;

to :

@BindView(R.id.ListView)
ListView mListView;

Upvotes: 1

Ajay P. Prajapati
Ajay P. Prajapati

Reputation: 2023

You are using listview id which is inbuild android.R.id.list which requires you to extend your activity with ListActivity.

So extend your activity with ListActivity. like this

public class MainActivity extends ListActivity

Or, If you use use custom listview with your id, then use same activity, just give proper id which you defined in your xml file and initialize it.

Something like this 

 ListView list = (ListView) view.findViewById(R.id.yourlistviewid);

Upvotes: 0

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