如何在 Swift 中旋轉 UIAlertController

Question

我有一個工作的UIAlertController ，但我想將alert.view向左旋轉 90 度。

我該怎么做？ 我的代碼如下：

let alert = UIAlertController(title: "", message: "Message Sample", preferredStyle: .Alert)
alert.addAction(UIAlertAction(title: "Okay", style: .Default){(action)->() in })
presentViewController(alert, animated: true) {}

我試圖添加：

 alert.view.transform = CGAffineTransformMakeRotation(CGFloat(M_PI_2))

但它不起作用。

謝謝 ！

Answer 1

使用此代碼：

let alert = UIAlertController(title: "", message: "Message Sample", preferredStyle: .Alert)
alert.addAction(UIAlertAction(title: "Okay", style: .Default){(action)->() in })

self.presentViewController(alert, animated: true, completion: {() -> Void in
      alert.view.transform = CGAffineTransformMakeRotation(CGFloat(M_PI_2))

})

Swift3

let alert = UIAlertController(title: "", message: "Message Sample", preferredStyle: .alert)
    alert.addAction(UIAlertAction(title: "Okay", style: .default){(action)->() in })

    self.present(alert, animated: true, completion: {() -> Void in
        alert.view.transform = CGAffineTransform(rotationAngle: CGFloat(Double.pi/2) )

    })

你可以實現這個目標：

更新的答案

 self.presentViewController(alert, animated: true, completion: {() -> Void in
         // alert.view.transform = CGAffineTransformMakeRotation(CGFloat(M_PI_2))

        UIView.animateWithDuration(1.0, delay: 0, options: .CurveLinear, animations: { () -> Void in
            alert.view.transform = CGAffineTransformMakeRotation(CGFloat(M_PI_2))
        }) { (finished) -> Void in
          // do something if you need
        }

    })

Answer 2

我認為這可能會更常出現在FaceID上。 我必須解決這個問題，因為我有一個處於橫向模式的應用程序，但是當用戶在iPhone上啟動應用程序或者當他們必須使用FaceID對應用程序進行身份驗證時，它們通常是縱向的。 所以我想根據用戶拿着手機的方式顯示提醒。 我的解決方案是擴展UIAlertController類，如下所示;

extension UIAlertController {
    open override func viewWillAppear(_ animated: Bool) {
        view.isHidden = true
    }
    override open func viewDidAppear(_ animated: Bool) {
        let appDirection = UIApplication.shared.statusBarOrientation
        let deviceDirection = UIDevice.current.orientation
        var direction:CGFloat = 0
        if deviceDirection == .portrait {
            if appDirection == .landscapeLeft {
                direction = 1.0
            } else if appDirection == .landscapeRight {
                direction = -1.0
            }
        } else if deviceDirection == .portraitUpsideDown {
            if deviceDirection == .landscapeLeft {
                direction = -1.0
            } else if appDirection == .landscapeRight {
                direction = 1.0
            }
        }
        if direction != 0 {
           view.transform = CGAffineTransform(rotationAngle: CGFloat(Double.pi / 2) * direction);
        }
        view.isHidden = false
    }
    open override func viewWillDisappear(_ animated: Bool) {
        view.isHidden = true
    }
}

Answer 3

如果您的應用程序支持landscapeRight，landscapeLeft和default（如肖像），您可以嘗試這樣做

self.present(alertController, animated: false, completion: {
            switch UIDevice.current.orientation {
            case .landscapeRight:
                self.alertController.view.transform=CGAffineTransform(rotationAngle: CGFloat(-Double.pi / 2))
            case .landscapeLeft:
                self.alertController.view.transform=CGAffineTransform(rotationAngle: CGFloat(Double.pi / 2))
            default:
                self.alertController.view.transform=CGAffineTransform.identity
            }
        })

這將根據您的屏幕旋轉旋轉警報視圖，而不會出現任何UI動畫問題。

Answer 4

我受到 Nico Nierenberg 的回答的啟發，但用一些 Core Animation 邏輯對其進行了擴充。 這個額外的邏輯是使警報在其呈現和關閉期間旋轉所必需的 animation（Nico 的原始實現只是隱藏警報，這將給出與為animated傳遞false相同的外觀）。

我還添加了一個通知偵聽器，它在設備方向改變時調整旋轉。

此實現假定您的原始演示文稿僅是縱向的。 如果您呈現的 controller 可以在其他方向，您將需要修復radians方法。

這是整個 class：

import UIKit

class RotatingAlertController : UIAlertController {
    private static let animKey = "rotationHack"
    private func radians(for orientation: UIDeviceOrientation) -> CGFloat {
        switch orientation {
        case .landscapeLeft: return CGFloat.pi*0.5
        case .portraitUpsideDown: return CGFloat.pi*1
        case .landscapeRight: return CGFloat.pi*1.5
        default: return 0
        }
    }
    private func applyCoreAnimationRotation() {
        let rotationValue = radians(for: UIDevice.current.orientation)
        let anim = CABasicAnimation(keyPath: "transform.rotation.z")
        anim.duration = 9999
        anim.toValue = rotationValue
        anim.fromValue = rotationValue
        view.layer.add(anim, forKey: RotatingAlertController.animKey)
    }
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        applyCoreAnimationRotation()
    }
    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        view.layer.removeAnimation(forKey: RotatingAlertController.animKey)
        view.transform = CGAffineTransform(rotationAngle: radians(for: UIDevice.current.orientation))
        weak var weakSelf = self
        NotificationCenter.default.addObserver(forName: UIDevice.orientationDidChangeNotification,
                                               object: nil,
                                               queue: nil) { _ in
            guard let strongSelf = weakSelf else { return }
            let orientation = UIDevice.current.orientation
            guard orientation != .unknown &&
                  orientation != .faceDown &&
                  orientation != .faceUp
            else {
                return
            }
            UIView.animate(withDuration: 0.25, delay: 0) {
                strongSelf.view.transform = CGAffineTransform(rotationAngle: strongSelf.radians(for: orientation))
            }
        }
    }
    override func viewWillDisappear(_ animated: Bool) {
        NotificationCenter.default.removeObserver(self)
        applyCoreAnimationRotation()
    }
}

您可以像這樣調用它：

let alert = RotatingAlertController(title: "Title", message: "Message", preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "OK", style: .default))
present(alert, animated: true)