如何在gridview适配器中回收位图？

public class MyAdapter extends BaseAdapter {
    private Context mContext;
    private List<String> mImageUrls;
    private LayoutInflater mInflater;

    public MyAdapter(Context context, List<String> imageUrls) {
        mContext = context;
        mImageUrls = imageUrls;
        mInflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        return mImageUrls.size();
    }

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

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.grid_item, parent, false);
            holder = new ViewHolder();
            holder.imageView = convertView.findViewById(R.id.image_view);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
            // 回收之前的位图
            if (holder.bitmap != null) {
                holder.bitmap.recycle();
            }
        }

        // 加载位图
        Bitmap bitmap = loadBitmap(position);
        holder.imageView.setImageBitmap(bitmap);
        holder.bitmap = bitmap;

        return convertView;
    }

    private Bitmap loadBitmap(int position) {
        // 加载位图的逻辑
        // 使用BitmapFactory.Options的inBitmap属性来复用位图
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inBitmap = holder.bitmap;
        return BitmapFactory.decodeFile(mImageUrls.get(position), options);
    }

    private static class ViewHolder {
        ImageView imageView;
        Bitmap bitmap;
    }
}