优化ListView提升运行效率

优化

public View getView(int position, View convertView, ViewGroup parent) {
        //LauoutInflater
        ViewHolder vh = null;
        Student student = mData.get(position);
        if (convertView == null) {
            vh=new ViewHolder();
            convertView = mInflater.inflate(R.layout.list_simple_item, null);
            vh.name = (TextView) convertView.findViewById(R.id.name);
            vh.age = (TextView) convertView.findViewById(R.id.age);
            vh.sex = (TextView) convertView.findViewById(R.id.sex);
            vh.hobby = (TextView) convertView.findViewById(R.id.hobby);
            vh.img = (ImageView) convertView.findViewById(R.id.img);
            convertView.setTag(vh);
        } else {
            vh = (ViewHolder) convertView.getTag();
        }


        vh.name.setText(student.getName());
        vh.age.setText(student.getAge());
        vh.sex.setText(student.getSex());
        vh.hobby.setText(student.getHobby());
        vh.img.setImageResource(student.getImg());
        return convertView;


    }

    class ViewHolder {
        TextView name;
        TextView age;
        TextView sex;
        TextView hobby;
        ImageView img;

    }