ios - 当 iPad 旋转时，ActionSheet 的 PopoverController 不会停留在窗口的中心

Question

我有一个注销按钮，它显示一个操作表，该操作表使用以下代码将 iPad 上的弹出窗口直接置于窗口中间:

popoverController.sourceRect = CGRect(x: window.bounds.midX, y: window.bounds.midY, width: 0, height: 0)
popoverController.permittedArrowDirections = []

此处显示在窗口中间:

但是当我旋转 iPad 时，它会将自己定位到左下角:

为什么我旋转 iPad 时它不会停留在窗口的中央？我该如何修复它以使其保持在旋转中心？

操作表:

fileprivate func logOut(){

    let actionSheet = UIAlertController(title: nil, message: "Are you sure you want to log out?", preferredStyle: .actionSheet)

    let cancelActionButton = UIAlertAction(title: "Cancel", style: .destructive){ (action) in
        // ...
    }

    let logoutActionButton = UIAlertAction(title: "Log Out", style: .default){ (action) in
         // ...
     }

    actionSheet.addAction(logoutActionButton)
    actionSheet.addAction(cancelActionButton)

    if let popoverController = actionSheet.popoverPresentationController{
        popoverController.popoverBackgroundViewClass = PopoverBackgroundView.self

        popoverController.sourceView = view
        guard let window = UIApplication.shared.keyWindow else {
            popoverController.sourceView = view
            popoverController.sourceRect = CGRect(x: view.bounds.midX, y: view.bounds.midY, width: 0, height: 0)
            popoverController.permittedArrowDirections = []
            return
        }
        window.backgroundColor = .clear
        popoverController.sourceRect = CGRect(x: window.bounds.midX, y: window.bounds.midY, width: 0, height: 0)
        popoverController.permittedArrowDirections = []
    }
    tabBarController?.present(actionSheet, animated: true, completion: nil)
}

UIPopoverBackgroundView 的子类:

class PopoverBackgroundView: UIPopoverBackgroundView {

    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = UIColor.white
    }

    convenience required init(coder aDecoder: NSCoder) {
        self.init(frame: CGRect.zero)
    }

    override func layoutSubviews() {
        super.layoutSubviews()
    }

    override var arrowOffset: CGFloat {
        get {
            return 0.0
        }
        set {
        }

    }

    override var arrowDirection: UIPopoverArrowDirection {
        get {
            return UIPopoverArrowDirection.up
        }
        set {
        }
    }

    override class func contentViewInsets() -> UIEdgeInsets {
        return UIEdgeInsetsMake(10.0, 10.0, 10.0, 10.0)
    }

    override class func arrowBase() -> CGFloat {
        return 0.0
    }

    override class func arrowHeight() -> CGFloat {
        return 0.0
    }

    override class var wantsDefaultContentAppearance: Bool {
        get {
            return false
        }
    }
}

Answer 1

您应该在设备旋转时更新框架:

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
    let bounds = UIApplication.shared.keyWindow?.bounds ?? view.bounds
    currentActionSheet?.popoverPresentationController?.sourceRect = CGRect(x: bounds.midX, y: bounds.midY, width: 0, height: 0)
}

您需要将 UIAlertController 或 popoverController 保存到一个变量

weak var currentActionSheet : UIAlertController?