当我单击按钮时，我通过以下方式设置按钮的动画以更改图像：

@IBAction func btn_lockdragg(sender: UIButton) {

    sender.isSelected = !sender.isSelected
        
        if sender.isSelected == true {
            
            UIView.transition(with: sender as UIView, duration: 1.0, options: .transitionFlipFromRight, animations: {
                
                sender.setImage(UIImage(systemName: "lock"), for: .normal)
                        }, completion: nil)
          
            
        } else {
            
            
            UIView.transition(with: sender, duration: 1.0, options: .transitionFlipFromLeft, animations: {
                
                sender.setImage(UIImage(systemName: "lock.open"), for: .normal)
                        }, completion: nil)
        }
        



}

请问我怎样才能改变动画的背景色？我仍然需要按钮的背景色。