关于Adapter的优化

public class Adapter extends BaseAdapter {
private Context context;
private List<News> listNews;

static class ViewHolder{
private SmartImageView iamge;
private TextView tvTitle,tvDec,tvCom;

}


public Adapter(Context context, List<News> listNews) {
super();
this.context = context;
this.listNews = listNews;
}


public int getCount() {
// TODO Auto-generated method stub
return listNews.size();
}


public Object getItem(int arg0) {
// TODO Auto-generated method stub
return listNews.get(arg0);
}


public long getItemId(int arg0) {
// TODO Auto-generated method stub
return arg0;
}


public View getView(int arg0, View arg1, ViewGroup arg2) {

ViewHolder viewHolder=null;

if (arg1==null) {
viewHolder=new ViewHolder();
arg1=LayoutInflater.from(context).inflate(R.layout.list_item, null);
viewHolder.iamge=(SmartImageView) arg1.findViewById(R.id.iv_new);
viewHolder.tvTitle=(TextView) arg1.findViewById(R.id.tv_titile);
viewHolder.tvDec=(TextView) arg1.findViewById(R.id.tv_des);
viewHolder.tvCom=(TextView) arg1.findViewById(R.id.tv_com);
arg1.setTag(viewHolder);
}
else{
viewHolder=(ViewHolder) arg1.getTag();
}
viewHolder.iamge.setImageUrl(listNews.get(arg0).getImagePath());
viewHolder.tvTitle.setText(listNews.get(arg0).getTitle());
viewHolder.tvDec.setText(listNews.get(arg0).getDec());
viewHolder.tvCom.setText(listNews.get(arg0).getComm());

return arg1;
}


}