ios - My UIStepper is not animated -

i'm using uistepper added through storyboard. had iboulet reference uitableviewcell subclass , ibaction when stepper's value changed.

my problem when touch uistepper, there no animation. i'm quite new in ios dev can't find out why.

there header file:

//cellsubclass.h @interface saproductcell : uitableviewcell @property (weak, nonatomic) iboutlet uistepper *quantitystepper; - (ibaction)steppervaluechanged:(id)sender; 

and implementation:

//cellsubclass.m - (id)initwithstyle:(uitableviewcellstyle)style reuseidentifier:(nsstring*)reuseidentifier {    self = [super initwithstyle:style reuseidentifier:reuseidentifier];    if (self) {        self.quantitystepper.minimumvalue = 0;        self.quantitystepper.stepvalue = 0;        self.quantitystepper.value = 1;    }    return self; } // ... - (ibaction)steppervaluechanged:(id)sender{     self.quantity = [[nsnumber alloc] initwithdouble:([self.quantitystepper value])] ;     //[self refreshui]; --> works fine !! there no animation when touch down stepper }