iOS 动画两个 View ，彼此堆叠

Question

我在为两个 View 设置动画时遇到问题!

我有两个按钮，它们将从底部向上滑动不同的 View 。

我想做的事情是:

我正在像这样设置 RegisterView 动画:

class ViewController: UIViewController {

@IBOutlet weak var registerViewHeight: NSLayoutConstraint!
@IBOutlet weak var registerView: UIView!
@IBOutlet weak var registerViewBottomContraint: NSLayoutConstraint!

override func viewDidLoad() {
        super.viewDidLoad()

        self.registerViewBottomContraint.constant = -registerViewHeight.constant

    }

@IBAction func registerButtonPressed(_ sender: AnyObject) {
        self.registerViewBottomContraint.constant = 0
        UIView.animate(withDuration: 0.4, animations: {
            self.view.layoutIfNeeded()
        })

    }

第一:如何正确地将堆叠 View 添加到彼此之上？ 第二:有没有办法轻松地从按钮到 View 的转换？

非常感谢:)

Answer 1

您可以像这样为 View 设置动画 [Objective-C]:

CGRect viewFrame = self.registerView.frame;
self.registerView.frame = CGRectMake(viewFrame.origin.x, viewFrame.origin.y + viewFrame.size.height, viewFrame.size.width, viewFrame.size.height);
self.registerView.alpha = 0.0;

[UIView animateWithDuration:ANIMATION_DURATION
                      delay:0
                    options:UIViewAnimationOptionCurveEaseOut
                 animations:^{
                     self. registerView.frame = viewFrame;
                     self. registerView.alpha = 1.0;
                 }
                 completion:^(BOOL finished) {

                 }];