我在使用 RecyclerView 应用 SearchView 时遇到问题

Question

I am trying to implement the SearchView from the support library. I want the user to be to use the SearchView to filter a List of Words in a RecyclerView.

I have followed a few tutorials so far and I have added the SearchView to the ActionBar, But When the application starts everything works fine but when I click on the Search Icon. The app shows the following Error in the Logcat for a second and automatically app restarts and the error disappears. But the Search Functionality is not working

Error I received Error Image

This is my SearchActivity:

enter code here

public class SearchActivity extends AppCompatActivity {

    private Toolbar mToolbar;
    private RecyclerView mRecyclerView;
    private RecyclerViewAdpater mAdpater;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_search);
        mToolbar=findViewById(R.id.toolbarSearch);
        setSupportActionBar(mToolbar);
        mRecyclerView=findViewById(R.id.recyclerViewSearch);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
        mAdpater=new RecyclerViewAdpater(DataSevices.mChineseColors,this);
        mRecyclerView.setAdapter(mAdpater);
    }

    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.toolbar_search_menu,menu);
        MenuItem item=menu.findItem(R.id.action_search);
        SearchView searchView=(SearchView) item.getActionView();
        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                mAdpater.getFilter().filter(newText);
                return false;
            }
        });
        return true;
    }
}

And this is my RecyclerView Adapter Class

public class RecyclerViewAdpater extends RecyclerView.Adapter<RecyclerViewAdpater.MyViewHolder> implements Filterable {

private List<ChineseLanguage> mChineseLanguages;
private List<ChineseLanguage> mChineseLanguagesFull;
private Context mContext;
private MediaPlayer mMediaPlayer;

public RecyclerViewAdpater(List<ChineseLanguage> chineseLanguages, Context context) {
    mChineseLanguages = chineseLanguages;
    mChineseLanguagesFull=new ArrayList<>(mChineseLanguages);
    mContext = context;
}

@NonNull
@Override
public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view= LayoutInflater.from(parent.getContext()).inflate(R.layout.item_list,parent,false);
    return new MyViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull MyViewHolder holder, final int position) {
    holder.txtEnglishWord.setText(mChineseLanguages.get(position).getEnglishAlphabet());
    holder.txtChineseWord.setText(mChineseLanguages.get(position).getChineseAlphabet());
    holder.txtPronunciation.setText(mChineseLanguages.get(position).getPronounciation());

    holder.btnPlay.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            releasaMedia();
            mMediaPlayer=MediaPlayer.create(mContext,mChineseLanguages.get(position).getSound());
            mMediaPlayer.start();
            mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                @Override
                public void onCompletion(MediaPlayer mp) {
                    releasaMedia();
                }
            });

        }
    });

}

private void releasaMedia(){
    if (mMediaPlayer!=null){
        mMediaPlayer.release();
    }
    mMediaPlayer=null;
}

@Override
public int getItemCount() {
    return mChineseLanguages.size();
}

@Override
public Filter getFilter() {
    return filter;
}

private Filter filter=new Filter() {
    @Override
    protected FilterResults performFiltering(CharSequence constraint) {
        List<ChineseLanguage> filteredList=new ArrayList<>();
        if (constraint.toString().isEmpty()){
            filteredList.addAll(mChineseLanguagesFull);
        }else {
            for(ChineseLanguage item: mChineseLanguagesFull){
                if (item.getEnglishAlphabet().toLowerCase().contains(constraint.toString().toLowerCase().trim())){
                    filteredList.add(item);
                }
            }
        }
        FilterResults filterResults=new FilterResults();
        filterResults.values=filteredList;
        return filterResults;
    }

    @Override
    protected void publishResults(CharSequence constraint, FilterResults results) {
      mChineseLanguages.clear();
      mChineseLanguages.addAll((Collection<? extends ChineseLanguage>) results.values);
      notifyDataSetChanged();
    }

    };


    public class MyViewHolder extends RecyclerView.ViewHolder {

    TextView txtEnglishWord,txtChineseWord,txtPronunciation;
    ImageButton btnPlay;

    public MyViewHolder(@NonNull View itemView) {
        super(itemView);
        txtEnglishWord=itemView.findViewById(R.id.txtEnglishWord);
        txtChineseWord=itemView.findViewById(R.id.txtChineseWord);
        txtPronunciation=itemView.findViewById(R.id.txtPronunciation);
        btnPlay=itemView.findViewById(R.id.btnPlay);
    }
}

}

Please correct me if I have done anything wrong

Answer 1

Your leak is most likely happening because your adapter is still alive even after activity is dead and it carries the activity's context causing the memory leak. It's not required to pass context through activity, you can get it from within the class. Here instead of declaring global mContext variable in the adapter class, you can simply get your context in the following way:

public class MyViewHolder extends RecyclerView.ViewHolder {

  TextView txtEnglishWord,txtChineseWord,txtPronunciation;
  ImageButton btnPlay;
  View mItemView; //declare a global view variable

  public MyViewHolder(@NonNull View itemView) {
      super(itemView);
      mItemView = itemView; //assign itemView to the above declared global field
      txtEnglishWord=itemView.findViewById(R.id.txtEnglishWord);
      txtChineseWord=itemView.findViewById(R.id.txtChineseWord);
      txtPronunciation=itemView.findViewById(R.id.txtPronunciation);
      btnPlay=itemView.findViewById(R.id.btnPlay);
  }
}

Then in your onBindViewHolder get context from itemView

@Override
public void onBindViewHolder(@NonNull MyViewHolder holder, final int position) {
Context mContext = holder.itemView.getContext(); //access the declared field through the holder instance here
// your method here...
}

EDIT: I'd also suggest to check your publishResults method. To see if the problem is in notifydatasetchanged() try to re-initialize the mChineseLanguages list in the method. Also, in the constructor of adapter initialize the mChineseLanguages the same way as mChineseLanguagesAll.