迅速下降

Question

全部，

我想创建一个存储 UIScrollViews 等的下拉列表

我通过使用动画块做了很多这样的事情 - 从 x = 30 到 x = 400 ，所以它把盒子放下了。当成功块运行时，它会将 UIScollview 从 hidden = false .. 所以它在完成动画后显示 UIScoll 视图。

这是最好的方法吗？我正在努力实现这些结果

这是暴露的过滤器。所以动画运行以降低蓝色，然后我取消隐藏滚动视图。

这是之前的图像，当滤镜未曝光时。

因此在 NAV 栏下方有一个蓝色位。

谁能帮帮我，或者这是后面的练习？

Answer 1

如果您的目标是 iOS 7 或更高版本，您可以通过在下拉视图中放置两个具有不同优先级的高度约束来实现这一点，例如优先级 750 和显示状态的下拉高度常数以及 700 优先级和常数 0用于隐藏状态。接下来为了显示/隐藏下拉菜单，只需调用以下函数：

func showView(dropDownView: UIView) {

    let constrains = (dropDownView.superview?.constraints() as [NSLayoutConstraint]) +
            (dropDownView.constraints() as [NSLayoutConstraint])
    for constrain  in constrains{

        if(constrain.priority == 650{

            constrain.priority = 750

       }

    }

    dropDownView.hidden = false
    UIView.animateWithDuration(0.4, animations: {
        dropDownView.alpha = 1
        dropDownView.superview?.layoutIfNeeded()
        }, completion: {
        (value: Bool) in

    })


}

func hideView(dropDownView: UIView) {

    let constrains = (dropDownView.superview?.constraints() as [NSLayoutConstraint]) +
            (dropDownView.constraints() as [NSLayoutConstraint])
    for constrain  in constrains{

        if(constrain.priority == 750{

            constrain.priority = 650

       }

    }

    UIView.animateWithDuration(0.4, animations: {
        dropDownView.alpha = 0
        dropDownView.superview?.layoutIfNeeded()
        }, completion: {
        (value: Bool) in
        dropDownView.hidden = true                       
    })


}

Answer 2

这个问题现在有点老了，但是如果有人来同样的话。 我建议必须看看这篇文章

Menu interface: Controller Libraries 感谢原作者Manoolia ;)

和Awesome-iOSgit repo

我最喜欢的一个是Yalantis/GuillotineMenu

示例代码

只需创建 MenuViewController

   class MenuViewController: UIViewController, GuillotineMenu {
    //GuillotineMenu protocol
    var dismissButton: UIButton!
    var titleLabel: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()

        dismissButton = UIButton(frame: CGRectZero)
        dismissButton.setImage(UIImage(named: "ic_menu"), forState: .Normal)
        dismissButton.addTarget(self, action: "dismissButtonTapped:", forControlEvents: .TouchUpInside)

        titleLabel = UILabel()
        titleLabel.numberOfLines = 1;
        titleLabel.text = "Activity"
        titleLabel.font = UIFont.boldSystemFontOfSize(17)
        titleLabel.textColor = UIColor.whiteColor()
        titleLabel.sizeToFit()
    }

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        print("Menu: viewWillAppear")
    }

    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        print("Menu: viewDidAppear")
    }

    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)
        print("Menu: viewWillDisappear")
    }

    override func viewDidDisappear(animated: Bool) {
        super.viewDidDisappear(animated)
        print("Menu: viewDidDisappear")
    }

    func dismissButtonTapped(sende: UIButton) {
        self.presentingViewController?.dismissViewControllerAnimated(true, completion: nil)
    }

    @IBAction func menuButtonTapped(sender: UIButton) {
        self.presentingViewController?.dismissViewControllerAnimated(true, completion: nil)
    }

    @IBAction func closeMenu(sender: UIButton) {
        self.presentingViewController?.dismissViewControllerAnimated(true, completion: nil)
    }

}

extension MenuViewController: GuillotineAnimationDelegate {
    func animatorDidFinishPresentation(animator: GuillotineTransitionAnimation) {
        print("menuDidFinishPresentation")
    }
    func animatorDidFinishDismissal(animator: GuillotineTransitionAnimation) {
        print("menuDidFinishDismissal")
    }

    func animatorWillStartPresentation(animator: GuillotineTransitionAnimation) {
        print("willStartPresentation")
    }

    func animatorWillStartDismissal(animator: GuillotineTransitionAnimation) {
        print("willStartDismissal")
    }
}

并以这种方式在您的视图控制器中使用上面

class ViewController: UIViewController {

    let reuseIdentifier = "ContentCell"
    private let cellHeight: CGFloat = 210
    private let cellSpacing: CGFloat = 20
    private lazy var presentationAnimator = GuillotineTransitionAnimation()

    @IBOutlet var barButton: UIButton!

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        print("VC: viewWillAppear")
    }

    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        print("VC: viewDidAppear")
    }

    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)
        print("VC: viewWillDisappear")
    }

    override func viewDidDisappear(animated: Bool) {
        super.viewDidDisappear(animated)
        print("VC: viewDidDisappear")
    }


    override func viewDidLoad() {
        super.viewDidLoad()
        let navBar = self.navigationController!.navigationBar
        navBar.barTintColor = UIColor(red: 65.0 / 255.0, green: 62.0 / 255.0, blue: 79.0 / 255.0, alpha: 1)
        navBar.titleTextAttributes = [NSForegroundColorAttributeName: UIColor.whiteColor()]
    }

    @IBAction func showMenuAction(sender: UIButton) {
        let menuVC = storyboard!.instantiateViewControllerWithIdentifier("MenuViewController")
        menuVC.modalPresentationStyle = .Custom
        menuVC.transitioningDelegate = self
        if menuVC is GuillotineAnimationDelegate {
            presentationAnimator.animationDelegate = menuVC as? GuillotineAnimationDelegate
        }
        presentationAnimator.supportView = self.navigationController?.navigationBar
        presentationAnimator.presentButton = sender
        presentationAnimator.duration = 0.6
        self.presentViewController(menuVC, animated: true, completion: nil)
    }
}

// The following is just for the presentation. You can ignore it
extension ViewController: UICollectionViewDataSource, UICollectionViewDelegate {

    func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return 5
    }

    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell: AnyObject? = collectionView.dequeueReusableCellWithReuseIdentifier(reuseIdentifier, forIndexPath: indexPath)
        return cell as! UICollectionViewCell!
    }

    func collectionView(collectionView: UICollectionView,
                        layout collectionViewLayout: UICollectionViewLayout,
                        sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
        return CGSizeMake(CGRectGetWidth(collectionView.bounds) - cellSpacing, cellHeight)
    }
}

extension ViewController: UIViewControllerTransitioningDelegate {

    func animationControllerForPresentedController(presented: UIViewController, presentingController presenting: UIViewController, sourceController source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        presentationAnimator.mode = .Presentation
        return presentationAnimator
    }

    func animationControllerForDismissedController(dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        presentationAnimator.mode = .Dismissal
        return presentationAnimator
    }
}