CustomView inside RecyclerView

Question

I create custom view on Android. I need to use it as items to the listview.

My custom view:

public class CustomView extends View{
int random;

//4 constructors;

public int getRandom() {
    return random;
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    setMeasuredDimension(w, h);
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    canvas.drawBitmap(b, 0,0,new Paint());
    drawLetters(new Canvas(b));
}

private void init(){
    drawingUtil = DrawingUtil.getInstance(getContext());
    random = new Random().nextInt();
}

}

Adapter:

public class ListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    List<String> chapter = new ArrayList<>();
    Context context;
    LayoutInflater inflater;

    public ListAdapter(List<String> chapter, Context context) {
        this.chapter = chapter;
        this.context = context;
        this.inflater = LayoutInflater.from(context);
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v = inflater.inflate(R.layout.item, null);
        return new ChapterHolder(v);
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        ((ChapterHolder) holder).setVerse(chapter.get(position), position);
        Log.d(Constants.LOG_TAG, getClass().getSimpleName() + ": random " + ((ChapterHolder) holder).getRandom());
    }

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

}

the problem is that the contents of the custom view was repeated. to test I write in the log a random number generated in custom view class. When scrolling through the list that number repeated, even if i only scroll down. What I need to do to make each element do not repeat the contents?

Answer 1

From the first look of it it seems like you're creating one ViewHolder (ChapterHolder) but you're binding another (RecyclerView.ViewHolder). In your adapter declaration it should be:

public class ListAdapter extends RecyclerView.Adapter<ListAdapter.ChapterHolder>

and then your onBindViewHolder will actually bind the right holder... and will look like this:

    public void onBindViewHolder(ChapterHolder holder, int position) {
        holder.setVerse(chapter.get(position), position);
        Log.d(Constants.LOG_TAG, getClass().getSimpleName() + ": random " + 
        holder.getRandom());
    }