如何在 swift 中创建弹跳效果？

Question

I have created a popup in swift using UIView and I want to bounce it when displaying, but I don't know how to do that. I want to make the same effect as seen below:

Answer 1

You should use UIView.animate with usingSpringWithDamping and initialSpringVelocity parameters. Eg:

// Change position of view
UIView.animate(withDuration: 1.0, delay: 0.0, usingSpringWithDamping: 1.0, initialSpringVelocity: 0.0, options: [], animations: {
    // Call layoutIfNeeded()
})

Or you can change view's position in animation completion block. But it's not recommended.