ListView

        //convertView 历史缓存对象
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            TextView tv;
            if(convertView == null){
                //创建新的View对象
                tv = new TextView(MainActivity.this);
                System.out.println("创建新的View对象--"+position);
            }else{
                System.out.println("复用历史缓存对象--"+position);
                tv = (TextView) convertView;

            }
            tv.setText("哈哈哈"+position);
            return tv;
        }