用于国家标志和图像微调器的ArrayAdapter减慢了视图速度

Question

我有以下课程：

    private class CountryAdapter extends ArrayAdapter<String> {

    private LayoutInflater inflater;

    CountryAdapter(Context context, int textViewResourceId, ArrayList objects) {
        super(context, textViewResourceId, objects);
        inflater = getLayoutInflater();
    }

    @Override
    public View getDropDownView(int position, View convertView, @NonNull ViewGroup parent) {
        return getCustomDropdown(position, convertView, parent);
    }

    @NonNull
    @Override
    public View getView(int position, View convertView, @NonNull ViewGroup parent) {
        return getCustomView(position, convertView, parent);
    }

    View getCustomDropdown(int position, View convertView, ViewGroup parent) {
        DropViewHolder dropViewHolder;

        if (convertView == null) {
            dropViewHolder = new DropViewHolder();
            convertView = inflater.inflate(R.layout.country_spinner_row, parent, false);
            convertView.setTag(dropViewHolder);
            dropViewHolder.label = convertView.findViewById(R.id.spinner_countryNameRow);
            dropViewHolder.icon = convertView.findViewById(R.id.spinner_countryFlagRow);
        } else {
            dropViewHolder = (DropViewHolder) convertView.getTag();
        }

        dropViewHolder.label.setText(String.format("%s (+%s)", countryNameList.get(position), countryList.optJSONObject(position).optString("phoneCountryCode")));

        String flagPath = "flag_" + countryList.optJSONObject(position).optString("countryCode").toLowerCase();
        dropViewHolder.icon.setImageResource(getResources().getIdentifier(flagPath, "drawable", getPackageName()));

        return convertView;
    }

    View getCustomView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;

        if (convertView == null) {
            viewHolder = new ViewHolder();
            convertView = inflater.inflate(R.layout.country_spinner_row_dropdown, parent, false);
            convertView.setTag(viewHolder);
            viewHolder.icon = convertView.findViewById(R.id.spinner_countryFlagRow);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        String flagPath = "flag_" + countryList.optJSONObject(position).optString("countryCode").toLowerCase();            viewHolder.icon.setImageResource(getResources().getIdentifier(flagPath, "drawable", getPackageName()));

        return convertView;
    }

    private class DropViewHolder {
        TextView label;
        AdapterImageView icon;
    }

    private class ViewHolder {
        AdapterImageView icon;
    }
}

我认为它符合ArrayAdapter，重用视图等的所有标准。但是，当打开键盘时，视图会重新绘制，并且按钮位置更新存在很大的滞后性。

有什么明显的我想念吗？

先谢谢您了:)

编辑：为了更加清晰，AdapterImageView只是扩展ImageView并覆盖requestLayout的类，而无需调用super来防止昂贵的重绘。

EDIT2：相比之下，这段代码更旧，理论上讲性能更差，不会落后于UI。

 public class CountryAdapter extends ArrayAdapter<String> {

    public CountryAdapter(Context context, int textViewResourceId, ArrayList objects) {
        super(context, textViewResourceId, objects);
    }

    @Override
    public View getDropDownView(int position, View convertView, ViewGroup parent) {
        return getCustomView(position, convertView, parent);
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        return getCustomView(position, convertView, parent);
    }

    public View getCustomView(int position, View convertView, ViewGroup parent) {

        LayoutInflater inflater = getLayoutInflater();
        View row = inflater.inflate(R.layout.country_spinner_row, parent, false);
        TextView label = (TextView) row.findViewById(R.id.spinner_countryNameRow);
        label.setText(countryNameList.get(position).toString());


        ImageView icon = (ImageView) row.findViewById(R.id.spinner_countryFlagRow);
        String flagPath = "flag_" + countryList.optJSONObject(position).optString("countryCode").toLowerCase();

        icon.setImageResource(getResources().getIdentifier(flagPath, "drawable", getPackageName()));

        return row;
    }
}