Swift 5 & sheetPresentationController 传递数据

Question

我正在学习 swift 并尝试将变量传递给工作表，但是当工作表弹出时它并没有改变变量，有没有不同的方法来做到这一点？

let bottomSheet = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "bottomSheet")
    
    if let sheet = bottomSheet.sheetPresentationController{
        sheet.detents = [.medium()]
        sheet.prefersGrabberVisible = true
        sheet.preferredCornerRadius = 24
        sheet.prefersGrabberVisible = true
    }

    bottomSheet.isEnabled = true
    self.present(bottomSheet, animated: true, completion: nil)

在 bottomSheet 视图控制器中我有变量

var isEnabled: Bool = false

但即使我把它设置为 true，它总是显示为 false

Answer 1

像这样尝试，您需要做的是将其指定为视图控制器。

let mainStoryboard = UIStoryboard(name: "Main", bundle: nil)
if let bottomSheet = mainStoryboard.instantiateViewController(withIdentifier: "bottomSheet") as? BottomSheetVC{
        if let sheet = bottomSheet.sheetPresentationController{
            sheet.detents = [.medium()]
            sheet.prefersGrabberVisible = true
            sheet.preferredCornerRadius = 24
            sheet.prefersGrabberVisible = true
        }
        
        bottomSheet.isEnabled = true
        self.present(bottomSheet, animated: true)
    }

Answer 2

sheetPresentationController 仅适用于 ios 15 及更高版本，对于以前的版本，您需要设置 .custom modalPresentationStype

        controller.modalPresentationStyle = .pageSheet
        if #available(iOS 15.0, *) {

            if let sheet = controller.sheetPresentationController {
                sheet.detents = [.medium()]
            }
            
        } else {
            
            controller.modalPresentationStyle = .custom
            controller.transitioningDelegate = self
        }
        self.present(controller, animated: true, completion: nil)

// MARK: - UIViewControllerTransitioningDelegate

extension CPPdfPreviewVC: UIViewControllerTransitioningDelegate {


func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController? {
    PresentationController(presentedViewController: presented, presenting: presenting)
    }

并按给定添加演示控制器

class PresentationController: UIPresentationController {

  let blurEffectView: UIVisualEffectView!
  var tapGestureRecognizer: UITapGestureRecognizer = UITapGestureRecognizer()
  
  override init(presentedViewController: UIViewController, presenting presentingViewController: UIViewController?) {
      let blurEffect = UIBlurEffect(style: .dark)
      blurEffectView = UIVisualEffectView(effect: blurEffect)
      super.init(presentedViewController: presentedViewController, presenting: presentingViewController)
      tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(dismissController))
      blurEffectView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
      self.blurEffectView.isUserInteractionEnabled = true
      self.blurEffectView.addGestureRecognizer(tapGestureRecognizer)
  }
  
  override var frameOfPresentedViewInContainerView: CGRect {
      CGRect(origin: CGPoint(x: 0, y: self.containerView!.frame.height * 0.4),
             size: CGSize(width: self.containerView!.frame.width, height: self.containerView!.frame.height *
              0.6))
  }

  override func presentationTransitionWillBegin() {
      self.blurEffectView.alpha = 0
      self.containerView?.addSubview(blurEffectView)
      self.presentedViewController.transitionCoordinator?.animate(alongsideTransition: { (UIViewControllerTransitionCoordinatorContext) in
          self.blurEffectView.alpha = 0.7
      }, completion: { (UIViewControllerTransitionCoordinatorContext) in })
  }
  
  override func dismissalTransitionWillBegin() {
      self.presentedViewController.transitionCoordinator?.animate(alongsideTransition: { (UIViewControllerTransitionCoordinatorContext) in
          self.blurEffectView.alpha = 0
      }, completion: { (UIViewControllerTransitionCoordinatorContext) in
          self.blurEffectView.removeFromSuperview()
      })
  }
  
  override func containerViewWillLayoutSubviews() {
      super.containerViewWillLayoutSubviews()
    presentedView!.roundCorners([.topLeft, .topRight], radius: 22)
  }

  override func containerViewDidLayoutSubviews() {
      super.containerViewDidLayoutSubviews()
      presentedView?.frame = frameOfPresentedViewInContainerView
      blurEffectView.frame = containerView!.bounds
  }

  @objc func dismissController(){
      self.presentedViewController.dismiss(animated: true, completion: nil)
  }
}

extension UIView {
  func roundCorners(_ corners: UIRectCorner, radius: CGFloat) {
      let path = UIBezierPath(roundedRect: bounds, byRoundingCorners: corners,
                              cornerRadii: CGSize(width: radius, height: radius))
      let mask = CAShapeLayer()
      mask.path = path.cgPath
      layer.mask = mask
  }
}

    }