Android Adapter ViewHolder
Android 的 ViewHolder 相信大家都有接觸過,
但是那個程式碼實在很醜很煩,
找到了一種比較簡潔的寫法,
分享給大家,
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;
}
}
useage
@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;
}