优化代码

class  adapter extends BaseAdapter{    @Override    public int getCount() {        return datas.size();    }    @Override    public Object getItem(int position) {        return datas.get(position);    }    @Override    public long getItemId(int position) {        return position;    }    @Override    public View getView(int position, View convertView, ViewGroup parent) {        Viewholder holder;        if (convertView==null) {            convertView=View.inflate(MainActivity.this,R.layout.lv_one,null);            holder=new Viewholder();            holder.one=convertView.findViewById(R.id.textView);            holder.two=convertView.findViewById(R.id.textView2);            holder.im=convertView.findViewById(R.id.imageView);            convertView.setTag(holder);        }else {            holder=(Viewholder) convertView.getTag();        }        holder.one.setText(datas.get(position).getTitle());        holder.two.setText(datas.get(position).getContent());        ImageLoader.getInstance().displayImage(datas.get(position).getImg(),holder.im);        return convertView;    }}

////////////////////////////class Viewholder{    TextView one ,two;    ImageView im;}