ios - Swift 3 - adaptivePresentationStyle 永远不会被调用

Question

我正在尝试在 iPhone 中显示弹出窗口。我遵循我在此处找到的建议并使用委托(delegate)“adaptivePresentationStyle”，但从未调用过此函数，并且 ViewController 将始终以全屏模式显示。我有“UIPopoverPresentationControllerDelegate”和以下功能:

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

        let identifier  = segue.destination.restorationIdentifier ?? ""
        if identifier == "NavigationSetup" {
            if let destinationNav   = segue.destination as? UINavigationController {
                let destination  = destinationNav.topViewController as! SetupTableViewController
                destination.popoverPresentationController?.delegate = self
                destination.popoverPresentationController?.backgroundColor  = UIColor.blue
                if self.myApp.isIpad{
                    destination.preferredContentSize  = CGSize(width: 600, height: 620)
                }else{
                    destination.preferredContentSize  = CGSize(width: 0.8 * self.view.frame.size.width, height: 0.8 * self.view.frame.size.height)
                }

                self.cellAnimations.fade(image: self.imageBlur, initOpacity: 0, endOpacity: 1, time: 0.3, completion: nil)
                destination.setupDismiss = {[weak self] () in
                    if let weakSelf = self{
                        weakSelf.cellAnimations.fade(image: weakSelf.imageBlur, initOpacity: 1, endOpacity: 0, time: 0.3, completion: nil)
                    }
                }

            }
        }

    }
    func adaptivePresentationStyle(for controller:UIPresentationController) -> UIModalPresentationStyle {
        print("adaptive was called")
        return .none
    }

那么，我在这里缺少什么？

Answer 1

首先，设置断点以确保调用此行:

destination.popoverPresentationController?.delegate = self

更好的是，像这样重写，并设置一个断点以确保正在调用内线:

if let pop = destination.popoverPresentationController {
    pop.delegate = self
}

如果是，那就太好了!在那种情况下，问题可能是实现了错误的委托(delegate)方法。你想要这个:

func adaptivePresentationStyle(for controller: UIPresentationController, 
    traitCollection: UITraitCollection) -> UIModalPresentationStyle {