ListView重写Adapter优化上下滚动响应速度

主要是重写Adapter的getView方法，执行时不用每次都创建一次对象。

// Music list adapterpublic static class MusicListAdapter extends SimpleAdapter {private LayoutInflater mInflater; private List<? extends Map<String, ?>> mList; public MusicListAdapter(Context context, List<? extends Map<String, ?>> data, int resource, String[] from, int[] to) { super(context, data, resource, from, to); mInflater = LayoutInflater.from(context); mList = data; }@Overridepublic int getCount() {// TODO Auto-generated method stubreturn super.getCount();}@Overridepublic Object getItem(int position) {// TODO Auto-generated method stubreturn super.getItem(position);}@Overridepublic long getItemId(int position) {// TODO Auto-generated method stubreturn super.getItemId(position);}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {// 优化list速度ViewHolder holder = null;if (convertView == null) {convertView = mInflater.inflate(R.layout.list_items, null);holder = new ViewHolder();holder.ItemTitle = (TextView) convertView.findViewById(R.id.ItemTitle);holder.ItemSinger = (TextView) convertView.findViewById(R.id.ItemSinger);holder.ItemTime = (TextView) convertView.findViewById(R.id.ItemTime);convertView.setTag(holder);} else {holder = (ViewHolder) convertView.getTag();}holder.ItemTitle.setText((String)mList.get(position).get("ItemTitle"));holder.ItemSinger.setText((String)mList.get(position).get("ItemSinger"));holder.ItemTime.setText((String)mList.get(position).get("ItemTime"));return convertView;}static class ViewHolder {TextView ItemTitle;TextView ItemSinger;TextView ItemTime;}}