ListView在下拉时出现空指针错误

来源：互联网发布：淘宝上架数量限制编辑：程序博客网时间：2024/05/29 23:48

原因出在adapter的getView方法中

原先的写法：

@Overridepublic View getView(int position, View convertView, ViewGroup parent) {View view = null;ViewHolder holder = null;if(convertView == null) {holder = new ViewHolder();LayoutInflater inflater = getLayoutInflater();view = inflater.inflate(R.layout.list_cell, null);holder.tvTitle = (TextView) view.findViewById(R.id.tv_title);holder.tvDetail = (TextView) view.findViewById(R.id.tv_content);holder.tvComment = (TextView) view.findViewById(R.id.tv_comment);} else {view = convertView;}holder.tvTitle.setText(newsList.get(position).getTitle());holder.tvDetail.setText(newsList.get(position).getDetail());holder.tvComment.setText(newsList.get(position).getComment() + "跟帖");return view;}

改正后写法：

@Overridepublic View getView(int position, View convertView, ViewGroup parent) {ViewHolder holder = null;if(convertView == null) {holder = new ViewHolder();LayoutInflater inflater = getLayoutInflater();convertView = inflater.inflate(R.layout.list_cell, null);holder.tvTitle = (TextView) convertView.findViewById(R.id.tv_title);holder.tvDetail = (TextView) convertView.findViewById(R.id.tv_content);holder.tvComment = (TextView) convertView.findViewById(R.id.tv_comment);convertView.setTag(holder);} else {holder = (ViewHolder) convertView.getTag();}holder.tvTitle.setText(newsList.get(position).getTitle());holder.tvDetail.setText(newsList.get(position).getDetail());holder.tvComment.setText(newsList.get(position).getComment() + "跟帖");return convertView;}

出现空指针的原因应该是ListView滑动后，原先的写法holder内的变量（tvTitle）不能找到了。

0 0