UILabel, UIView, UIButtonの角を丸くする

UILabelとUIViewの場合

 
UILabel *label =  [UILabel alloc]init];
label.clipsToBounds = true;
label.layer.cornerRadius = 3.0f;

UIView *view = [UIView alloc]init];
view.clipsToBounds = true;
view.layer.cornerRadius = 3.0f;

UIButtonの場合

 
UIButton *button = [UIButton alloc]init];
button.layer.cornerRadius = 3.0f;