Swift:iOS 动画在查看消息控制器(iOS 的消息页面)后停止

Question

用户按下徽标后，我正在运行动画。这是动画：

func rightRotateView(targetView: UIView, duration: Double = 5) {
    UIView.animate(withDuration: duration, delay: 0.0, options: [.repeat, .curveLinear] , animations: {
        targetView.transform = targetView.transform.rotated(by: CGFloat.pi * 5)
    }) { finished in
       // self.rightRotateView(targetView: targetView)
    }
}

长按 3 秒后（此时动画仍应运行），我向用户显示消息控制器：

 if MFMessageComposeViewController.canSendText() == true {
        print(self.urgentNumber)
        let recipients:[String] = ["(self.urgentNumber as! String)"]
        self.messageController.messageComposeDelegate  = self as? MFMessageComposeViewControllerDelegate
        self.messageController.recipients = recipients
        self.messageController.body = "Hey,nmy longitude: (self.userLocation.coordinate.longitude) nmy latitude: (self.userLocation.coordinate.latitude)"
        self.present(self.messageController, animated: true, completion: nil)

    } else {
        //handle text messaging not available
    }

当我按下消息控件中的取消按钮时，我返回到动画页面，但动画停止工作。我试图在现在之后重新运行动画，并在

func messageComposeViewController(_ controller: MFMessageComposeViewController, didFinishWith result: MessageComposeResult) {
}

但它没有奏效。

Answer 1

我发现了问题，只需在完成中重新运行相同的动画，（您可以使用CABasicAnimation或简单地使用UIView.animate）：

func rightRotateView(targetView: UIView, duration: Double = 5) {
    UIView.animate(withDuration: duration, delay: 0.0, options: [.repeat, .curveLinear] , animations: {
        targetView.transform = targetView.transform.rotated(by: CGFloat.pi * 5)
    }) { finished in
        let anim = CABasicAnimation(keyPath:"transform.rotation")
        anim.fromValue = 0.000
        anim.toValue = 360.0
        anim.speed = 0.001
        anim.repeatCount = .infinity
        targetView.layer.add(anim, forKey: "transform.rotation")
    }
}

Answer 2

用于

此CABasicAnimation（keyPath： "transform.rotation"）