石家庄网站优化/关键词seo深圳

在使用自定义ListView视图时，经常会采用重用ListView中视图的方式来提高滑动和显示效率，但是随之而来的一个问题是listview中数据经常显示混乱。

通常情况下，我们重写的方法是这样的：

inflater = LayoutInflater.from(context);@Overridepublic View getView(int position, View convertView, ViewGroup parent) {ViewHolder holder;if (convertView == null) {convertView = inflater.inflate(R.layout.book_item, null);holder = new ViewHolder(convertView);Book book = books.get(position);holder.bookName.setText(book.getName());holder.bookTime.setText(book.getTime());convertView.setTag(holder);} else {holder = (ViewHolder) convertView.getTag();}return convertView;}class ViewHolder {ImageView bookPic;TextView bookName;TextView bookTime;public ViewHolder(View view) {bookPic = (ImageView) view.findViewById(R.id.iv_book_pic);bookName = (TextView) view.findViewById(R.id.tv_book_name);bookTime = (TextView) view.findViewById(R.id.tv_book_time);}}

这样通常会造成list显示混乱，是因为当我们重用视图但是convertView != null的时候我们并没有去重新加载数据，写成下面这种形式就会重新加载数据了：

@Overridepublic View getView(int position, View convertView, ViewGroup parent) {ViewHolder holder;if (convertView == null) {convertView = inflater.inflate(R.layout.book_item, null);holder = new ViewHolder(convertView);convertView.setTag(holder);} else {holder = (ViewHolder) convertView.getTag();}Book book = books.get(position);//不管视图是否重用，都重新设置数据holder.bookName.setText(book.getName());holder.bookTime.setText(book.getTime());return convertView;}