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，

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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

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@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;
}