public class ViewHolder { // I added a generic return type to reduce the casting noise in client code @SuppressWarnings("unchecked") public static <T extends View> T get(View view, int id) { SparseArray<View> viewHolder = (SparseArray<View>) view.getTag(); if (viewHolder == null) { viewHolder = new SparseArray<View>(); view.setTag(viewHolder); } View childView = viewHolder.get(id); if (childView == null) { childView = view.findViewById(id); viewHolder.put(id, childView); } return (T) childView; } }
使用方式如下:
@Override public View getView(int position, View convertView, ViewGroup parent) { if (convertView == null) { convertView = LayoutInflater.from(context) .inflate(R.layout.banana_phone, parent, false); } ImageView bananaView = ViewHolder.get(convertView, R.id.banana); TextView phoneView = ViewHolder.get(convertView, R.id.phone); BananaPhone bananaPhone = getItem(position); phoneView.setText(bananaPhone.getPhone()); bananaView.setImageResource(bananaPhone.getBanana()); return convertView; }
可以将此类添加到常用类库中,一劳永逸。