在滾動一些recyclerview的項目消失

Question

試圖建立一個圖像編輯應用程序。我使用水平方式的RecyclerView來顯示圖像的縮略圖。在啟動時所有縮略圖都正確顯示但滾動時一些縮略圖不可見。縮略圖顯示使用畢加索實現的顏色效果轉換庫。

XML

 <android.support.v7.widget.RecyclerView
        android:id="@+id/horizontal_recycler_view"
        android:layout_width="match_parent"
        android:layout_height="90dp"
        android:layout_above="@+id/rlBottom"
        android:layout_below="@+id/flPhoto"
        android:background="@color/grey"/>

適配器類

    public class FiltersAdapter extends RecyclerView.Adapter<FiltersAdapter.ViewHolder> {

    private Context mContext;
    private List<Type> mDataSet;
    private Uri selectedPhoto;

    public enum Type {
        Grayscale,
        Sepia,
        Contrast,
        Invert,
        Pixel,
        Sketch,
        Swirl,
        Brightness,
        Kuawahara,
        Vignette
    }

    public FiltersAdapter(Context context, List<Type> dataSet, Uri selectedPhoto) {
        mContext = context;
        mDataSet = dataSet;
        this.selectedPhoto = selectedPhoto;
    }

    @Override
    public FiltersAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(mContext).inflate(R.layout.list_item_layout, parent, false);
        return new ViewHolder(v);
    }

    @Override
    public void onBindViewHolder(FiltersAdapter.ViewHolder holder, int position) {
        switch (mDataSet.get(position)) {

            case Grayscale:
                Picasso.with(mContext)
                        .load(selectedPhoto)
                        .transform(new GrayscaleTransformation())
                        .into(holder.image);
                break;
            case Sepia:
                Picasso.with(mContext)
                        .load(selectedPhoto)
                        .transform(new SepiaFilterTransformation(mContext))
                        .into(holder.image);
                break;
            case Contrast:
                Picasso.with(mContext)
                        .load(selectedPhoto)
                        .transform(new ContrastFilterTransformation(mContext, 2.0f))
                        .into(holder.image);
                break;
            case Invert:
                Picasso.with(mContext)
                        .load(selectedPhoto)
                        .transform(new InvertFilterTransformation(mContext))
                        .into(holder.image);
                break;
            case Pixel:
                Picasso.with(mContext)
                        .load(selectedPhoto)
                        .transform(new PixelationFilterTransformation(mContext, 20))
                        .into(holder.image);
                break;
            case Sketch:
                Picasso.with(mContext)
                        .load(selectedPhoto)
                        .transform(new SketchFilterTransformation(mContext))
                        .into(holder.image);
                break;
            case Swirl:
                Picasso.with(mContext)
                        .load(selectedPhoto)
                        .transform(new SwirlFilterTransformation(mContext, 0.5f, 1.0f, new PointF(0.5f, 0.5f)))
                        .into(holder.image);

                break;
            case Brightness:
                Picasso.with(mContext)
                        .load(selectedPhoto)
                        .transform(new BrightnessFilterTransformation(mContext, 0.5f))
                        .into(holder.image);
                break;
            case Kuawahara:
                Picasso.with(mContext)
                        .load(selectedPhoto)
                        .transform(new KuwaharaFilterTransformation(mContext, 25))
                        .into(holder.image);
                break;
            case Vignette:
                Picasso.with(mContext)
                        .load(selectedPhoto)
                        .transform(new VignetteFilterTransformation(mContext, new PointF(0.5f, 0.5f),
                                new float[]{0.0f, 0.0f, 0.0f}, 0f, 0.75f))
                        .into(holder.image);
                break;
        }
        holder.title.setText(mDataSet.get(position).name());
    }

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

    @Override
    public int getItemViewType(int position) {
        return position;
    }

    static class ViewHolder extends RecyclerView.ViewHolder {

        public ImageView image;
        public TextView title;

        ViewHolder(View itemView) {
            super(itemView);
            image = (ImageView) itemView.findViewById(R.id.thumbnailImage);
            title = (TextView) itemView.findViewById(R.id.title);
        }
    }
}

Answer 1

使用if else條件在imageView中設置圖片並添加默認值