Create NumberPicker dialog in preference

Question

I am trying to create a NumberPicker dialog in my preference screen. I have already made one following this:https://stackoverflow.com/a/5533295/2442638

However, for

Answer 1

return a LinearLayout in onCreateDialogView rather than NumberPicker as below:

@Override
protected View onCreateDialogView() {
    numberPicker = new NumberPicker(getContext());
    numberPicker.setMinValue(1);
    numberPicker.setMaxValue(12);
    numberPicker.setWrapSelectorWheel(false);
    numberPicker.setValue(lastValue);

    LinearLayout.LayoutParams pickerParams = new LinearLayout.LayoutParams
            (LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
    pickerParams.gravity = Gravity.CENTER;
    numberPicker.setLayoutParams(pickerParams);

    LinearLayout layout = new LinearLayout(getContext());
    LinearLayout.LayoutParams params = new LinearLayout.LayoutParams
            (LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
    layout.setOrientation(LinearLayout.VERTICAL);
    layout.setLayoutParams(params);

    layout.addView(numberPicker);
    return layout;

    //return numberPicker;
}