微调器在滚动listview时自动重置值。但如果我的项目很少，他们可以在屏幕上没有滚动我的应用程序完美地工作。单击按钮时，我检查listview的数字选择器的值。任何帮助都将不胜感激。提前谢谢。
我的适配器：

public class ProductListAdapterforListView extends BaseAdapter {
    private Context mContext;
    private List<piatto> mProductList;
    Vibrator vibe;
    MediaPlayer mp ;
    //Constructor

    public ProductListAdapterforListView(Context mContext, List<piatto> mProductList) {
        this.mContext = mContext;
        this.mProductList = mProductList;
    }
    @Override
    public int getViewTypeCount() {

        return getCount();
    }

    @Override
    public int getItemViewType(int position) {

        return position;
    }

    @Override
    public int getCount() {
        return mProductList.size();
    }

    @Override
    public Object getItem(int position) {
        return mProductList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View v = View.inflate(mContext, R.layout.row_data_list, null);

        TextView n = (TextView)v.findViewById(R.id.namepiatto);
        TextView p = (TextView)v.findViewById(R.id.prezzopiatto);
        ImageView i = (ImageView) v.findViewById(R.id.imagepiatto);
        com.shawnlin.numberpicker.NumberPicker numberPicker =v.findViewById(R.id.number_picker);

        n.setText(mProductList.get(position).getNome());
        p.setText(mProductList.get(position).getPrezzo()+" €");
        Picasso.get().load(mProductList.get(position).getImmagine()).into(i);

        numberPicker.setOnScrollListener(new NumberPicker.OnScrollListener() {
            @Override
            public void onScrollStateChange(NumberPicker view1, int scrollState) {
                Vibrator vi = (Vibrator) view1.getContext().getSystemService(Context.VIBRATOR_SERVICE);
                vi.vibrate(12);
                mp = MediaPlayer.create(view1.getContext(),R.raw.sound);
                mp.start();
            }
        });

        return v;
    }

}