Dithering of icons in imitation iOS

#import   "LHViewController.h" #define  angeltorandian (x)    ((x)/180.0*m_pi) @interface   lhviewcontroller  () @property   (strong, nonatomic)  iboutlet uiimageview *imageview ; @end @implementation lhviewcontroller-  (void) viewdidload{    [super  viewdidload];// do any additional setup after loading the view,  typically from a nib.    uilongpressgesturerecognizer* longpress=[[ Uilongpressgesturerecognizer alloc]initwithtarget:self action: @selector (longpress:)];     [self.imageview addgesturerecognizer:longpress];} -(void) Longpress: (uilongpressgesturerecognizer*) longpress{    if  (longPress.state== Uigesturerecognizerstatebegan)  {        cakeyframeanimation*  anim=[CAKeyframeAnimation animation];        [email protected] "transform.rotation";         [ email protected][@ (Angeltorandian ( -7)), @ (Angeltorandian (7)), @ (Angeltorandian ( -7))];         anim.repeatCount=MAXFLOAT;         Anim.duration=0.2;        [self.imageview.layer addanimation:anim  forkey:nil];        self.btn.hidden=no;    } }-  (ibaction) Delete: (ID) sender {    [self.imageview removefromsuperview];     [self.btn removefromsuperview];} @end

The following are the results of the program running:

Dithering of icons in imitation iOS