android viewholder

 

ViewHolder不是Android的开发API，而是一种设计方法，就是设计个静态类，缓存一下，省得Listview更新的时候，还要重新操作。
    public View getView(int pos, View convertView, ViewGroup parent){

            ViewHolder holder;

            if (convertView == null) {

                convertView = mInflater.inflate(R.layout.list_item, null);

                holder.text = (TextView) convertView.findViewById( R.id.text));

                holder.icon = (ImageView) convertView.findViewButId( R.id.icon));

                convertView.setTag(holder);

                }

            else {

                holder = (ViewHolder) convertView.getTag();

                }

            holder.text.setText(DATA[pos]);

            holder.icon.setImageBitmap((pos & 1) == 1 ? mIcon1 : mIcon2);

                return convertView;

//                holder = new ViewHolder();

                }



//     ViewHolder 模式, 效率提高 50%

        static class ViewHolder {

            TextView text;

            ImageView icon;

            }