public class SumileNumberPickerDialog extends AlertDialog
程序猿：既然 Dialog 可以设置 Theme，那么 NumberPicker 是不是也可以呢？
A widget that enables the user to select a number form a predefined range. There are two flavors of this widget and which one is presented to the user depends on the current theme. If the current theme is derived from android.R.style.Theme the widget presents the current value as an editable input field with an increment button above and a decrement button below. Long pressing the buttons allows for a quick change of the current value. Tapping on the input field allows to type in a desired value. If the current theme is derived from android.R.style.Theme_Holo or android.R.style.Theme_Holo_Light the widget presents the current value as an editable input field with a lesser value above and a greater value below. Tapping on the lesser or greater value selects it by animating the number axis up or down to make the chosen value current. Flinging up or down allows for multiple increments or decrements of the current value. Long pressing on the lesser and greater values also allows for a quick change of the current value. Tapping on the current value allows to type in a desired value. For an example of using this widget, see android.widget.TimePicker.