Question

众所周知，常规UIViewController 的iOS 13+模态表示样式将默认为 .pageSheet 。如果要更改它，可以在显示时将其更改为所需的样式。我在我的应用程序中使用 MFMailComposeViewController 和 MFMessageComposeViewController 共享内容。在 MFMailComposeViewController 的情况下，当我选择 modalPresentationStyle = .fullScreen 时，它可以很好地工作... 但不是 MFMessageComposeViewController 的情况。请在下面找到代码段

        if (MFMessageComposeViewController.canSendText()) {
            let controller = MFMessageComposeViewController()
            controller.body = “Message Body”
            controller.messageComposeDelegate = self
            controller.modalPresentationStyle = .fullScreen
            self.present(controller, animated: true, completion: nil)
            self.trackEvent(shareType: "SMS")
        }
    }

Answer 1

虽然我无法回答关于*为什么不能对MFMessageComposeViewController使用.fullScreen的问题，但我可以告诉您，如果您实现自己的自定义转换，则会得到所需的行为。

这是您为视图控制器设置自定义过渡的方式：

var customTransitionDelegate = CustomTransition(presentAnimation: CustomActionSheetPresentationTransition(), dismissAnimation: CustomActionSheetDismissalTransition())

 if (MFMessageComposeViewController.canSendText()) {
     let controller = MFMessageComposeViewController()
     controller.body = "Message Body"
     controller.messageComposeDelegate = self
     controller.modalPresentationStyle = .custom
     controller.transitioningDelegate = customTransitionDelegate
     self.present(controller, animated: true, completion: nil)
 }

您还应该遵守委托，并在用户单击“取消”后检查结果以将其关闭：

    func messageComposeViewController(_ controller: MFMessageComposeViewController, didFinishWith result: MessageComposeResult) {
    switch result {
    case .cancelled:
        self.presentedViewController?.dismiss(animated: true, completion: nil)
    default: break
    }
}

演示逻辑

class CustomActionSheetPresentationTransition: NSObject, UIViewControllerAnimatedTransitioning {
private let duration = 0.6

func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
    guard let fromView = transitionContext.viewController(forKey: .from) else { return }
    guard let toView   = transitionContext.viewController(forKey: .to) else { return }

    var screenOffUp = CGAffineTransform()
    let container = transitionContext.containerView

    screenOffUp = CGAffineTransform(translationX: 0, y: -fromView.view.frame.height)
    toView.view.frame = CGRect(x: 0, y: UIScreen.main.bounds.height, width: fromView.view.frame.width, height: fromView.view.frame.height)

    toView.view.center.x = container.center.x
    container.addSubview(toView.view)

    UIView.animate(withDuration: duration, delay: 0.0, usingSpringWithDamping: 0.8, initialSpringVelocity: 0.8, options: [], animations: {
        toView.view.transform = screenOffUp
    }, completion: { (success) in
        transitionContext.completeTransition(success)
    })
}

func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
    return duration
}
}

解雇逻辑

class CustomActionSheetDismissalTransition: NSObject, UIViewControllerAnimatedTransitioning {
private let duration = 0.8

func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
    return duration
}

func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
    guard let fromView = transitionContext.viewController(forKey: .from) else { return }
    let screenOffDown = CGAffineTransform(translationX: 0, y: fromView.view.frame.height)

    UIView.animate(withDuration: duration, delay: 0.0, usingSpringWithDamping: 0.8, initialSpringVelocity: 0.8, options: [], animations: {
        fromView.view.transform = screenOffDown
    }, completion: { (success) in
        transitionContext.completeTransition(success)
    })
}

}

iOS 13 modalPresentationStyle = UIModalPresentationFullScreen无法用于MFMessageComposeViewController

1 个答案: