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;