UITabBarItem图片旋转问题

Question

我想在旋转UITabBarItem图像时旋转它。我在viewDidLoad的

的UITabBarController方法中使用了以下代码

    let plusView2 = self.tabBar.subviews[1]
    self.SecondItemImageView = plusView2.subviews.first as? UIImageView
    self.SecondItemImageView.contentMode = .center

    let pluseView3 = self.tabBar.subviews[2]
    self.ThirdItemImageView = pluseView3.subviews.first as? UIImageView
    self.ThirdItemImageView.contentMode = .center

，并在下面的代码中使用了旋转动画

public override func tabBar(_ tabBar: UITabBar, didSelect item: UITabBarItem) {
  if item.tag == 2 {

        UIView.animate(withDuration: 0.2, delay: 0.1, options: .curveEaseIn, animations: {
            self.SecondItemImageView.transform = CGAffineTransform(rotationAngle: CGFloat(Double.pi))
            UIView.animate(withDuration: 0.1, delay: 0.1, options: .curveEaseIn, animations: {
                self.SecondItemImageView.transform = CGAffineTransform(rotationAngle: CGFloat(Double.pi * 2))
            }, completion: nil)
        }) { (done) in
        }
    }
    else if item.tag == 3 {
        UIView.animate(withDuration: 0.2, delay: 0.1, options: .curveEaseIn, animations: {
            self.ThirdItemImageView.transform = CGAffineTransform(rotationAngle: CGFloat(Double.pi))
            UIView.animate(withDuration: 0.1, delay: 0.1, options: UIView.AnimationOptions.curveEaseIn, animations: { () -> Void in
                self.ThirdItemImageView.transform = CGAffineTransform(rotationAngle: CGFloat(Double.pi * 2))
            }, completion: nil)
        }) { (done) in

        }
    }
}

在故事板中设置标签2和3 现在，当点击标签号3时，按钮图像旋转可以正常工作，但是对于标签号2时，按钮图像不旋转。两个标签栏项目使用的相同代码不能工作。另外，如果条件正常但图像未旋转时，请检查何时点击2号标签按钮。