ios - UITextView 上的(缩放)变换动画

Question

我的目标是为嵌套在以模态方式呈现的 UIView 卡中的 UITextView 创建“冒泡”动画。

当卡片出现时，UITextView 似乎没有出现......是否有一些解决方法？下面是我迄今为止尝试过的代码...

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    DispatchQueue.main.async {
        UIView.animate(withDuration: 1, delay: 0.1, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.8, options: .curveEaseOut, animations: {
            self.cardView.transform = CGAffineTransform(scaleX: 1, y: 1)              
            self.messageTextView.transform = CGAffineTransform(scaleX: 1, y: 1)  
        }, completion: nil)            
    }
}

override func viewDidLoad() {
    super.viewDidLoad()
    cardView.transform = CGAffineTransform(scaleX: 0, y: 0)
    messageTextView.transform = CGAffineTransform(scaleX: 0, y: 0)
}

Answer 1

我不确定确切的设置，所以显示 Storyboard。我没有添加约束，而是在动画之前添加 setNeedsLayout 。希望它对您有用。

          override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        DispatchQueue.main.async {
            self.messageTextView.setNeedsLayout()
            UIView.animate(withDuration: 1, delay: 0.1, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.8, options: .curveEaseOut, animations: {
                self.cardView.transform = CGAffineTransform(scaleX: 1, y: 1)
                self.messageTextView.transform = CGAffineTransform(scaleX: 1, y: 1)
            }, completion: nil)
        }
    }