ViewHolder和SmartImage的使用

 private class NewsAdapter extends BaseAdapter {

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

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

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

        private class ViewHolder {
            SmartImageView Siv_newsInfoImg;
            TextView Tv_newsInfoTitle;
            TextView Tv_newsInfoTime;
            TextView Tv_newsInfoContent;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            NewsInfo news = newsInfoArray.get(position);
            ViewHolder holder;
            if (convertView == null) {
                convertView = LayoutInflater.from(getApplicationContext()).inflate(R.layout.newslist_item, parent, false);
                holder = new ViewHolder();
                holder.Siv_newsInfoImg = convertView.findViewById(R.id.Siv_newsInfoImg);
                holder.Tv_newsInfoTitle = convertView.findViewById(R.id.Tv_newsInfoTitle);
                holder.Tv_newsInfoTime = convertView.findViewById(R.id.Tv_newsInfoTime);
                holder.Tv_newsInfoContent = convertView.findViewById(R.id.Tv_newsInfoContent);
                convertView.setTag(holder);
            } else {
                holder = (ViewHolder) convertView.getTag();
            }
            holder.Siv_newsInfoImg.setImageUrl(news.getImageUrl(), R.drawable.ic_launcher_background, R.drawable.ic_launcher_background);
            holder.Tv_newsInfoTitle.setText(news.getTitle());
            holder.Tv_newsInfoTime.setText(news.getTime());
            holder.Tv_newsInfoContent.setText(news.getContent());

            return convertView;
        }
    }