ios - PopoverPresentationController 委托(delegate)方法未调用

Question

我有一个类可以在空的 swift 文件中构造 UIPopoverPresentationController:

import Foundation
import UIKit

class Popovers : NSObject, UIPopoverPresentationControllerDelegate {

    func presentLoginScreen() {
        // Presenting login Popover

        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        let loginScreen = storyboard.instantiateViewControllerWithIdentifier("LogInScreen")

        let window = UIApplication.sharedApplication().windows.last!
        let height = window.screen.bounds.size.height
        let width = window.screen.bounds.size.width

        loginScreen.modalPresentationStyle = UIModalPresentationStyle.Popover
        loginScreen.preferredContentSize = CGSizeMake(width * 0.85  , height * 0.35)

        let loginScreenPopover = loginScreen.popoverPresentationController
        loginScreenPopover?.permittedArrowDirections = UIPopoverArrowDirection.init(rawValue: 0)
        loginScreenPopover?.delegate = self
        loginScreenPopover?.sourceView = window.rootViewController?.view
        loginScreenPopover?.sourceRect = CGRectMake(CGRectGetMidX(window.screen.bounds), CGRectGetMidY(window.screen.bounds), 0, 0)

        window.rootViewController?.presentViewController(loginScreen, animated: true, completion: nil)

        let blur = UIVisualEffectView(effect: UIBlurEffect(style: .Light)) as UIVisualEffectView
        let bounds = window.screen.bounds
        blur.frame = bounds
        blur.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
        window.rootViewController!.view.addSubview(blur)

    }

    func adaptivePresentationStyleForPresentationController(controller: UIPresentationController) -> UIModalPresentationStyle {
        return UIModalPresentationStyle.None
    }

    func popoverPresentationControllerDidDismissPopover(popoverPresentationController: UIPopoverPresentationController) {
        // Remove blur layer
        print("method called")
        let window = UIApplication.sharedApplication().windows.last
        window?.subviews.last?.removeFromSuperview()


    }


}

但是每当我关闭 PopoverPresentationController 时，委托(delegate)方法 popoverPresentationControllerDidDismissPopover 就永远不会被触发。

我已将 loginScreenPopover 的委托(delegate)设置为 self，并让 Popovers 类继承自 UIPopoverPresentationControllerDelegate，但似乎都不起作用。

它是在 iPhone 上，如果这与问题相关的话。

Answer 1

我已经找到答案了。在 LogInScreen 的 ViewDidLoad() 中，我将委托(delegate)设置为:

self.popoverPresentationController.delegate = getPopovers()

其中 getPopovers() 函数是用于检索在代码中其他位置创建的 Popover 对象的函数。现在，在我的 Popovers 类中，我可以遵循 UIPopoverPresentationControllerDelegate 并使用这些方法。