swift - self.dismiss 重置父 View Controller 的屏幕数据

Question

我在 ParentViewController 中呈现一个 View Controller :

let item = getCurrentItem()
let presentViewController = viewController as! TestViewController
    presentViewController.id = item.id
    presentViewController.dismissController { // my custom delegate to inform the parent vc
        self.dismiss(animated: true, completion: nil) // presenting view controller is closing then viewWillAppear will be triggered
    }

self.present(presentViewController, animated: true, completion: nil)  

但是当调用dismiss时，ParentViewController的全局数组和变量会恢复到它们的初始值。

class ParentViewController {

    // MARK: - Stored Properties

    private let refreshControl = UIRefreshControl()
    private var items = [String:[Item]]()
    private var screenLoaded: Bool = false

    // MARK: - Controller Lifecycle

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        // after dismiss is called viewWillAppear gets hit but the "screenLoaded" is always false
        if !screenLoaded {
            screenLoaded = true                
        }

        // items is initialised as well
    }

    private func openPopover() {
       let item = getCurrentItem()
       let presentViewController = viewController as! TestViewController
           presentViewController.id = item.id
           presentViewController.dismissController { // my custom delegate to inform the parent vc
               self.dismiss(animated: true, completion: nil) // presenting view controller is closing then viewWillAppear will be triggered
        }

        self.present(presentViewController, animated: true, completion: nil)   
    }
}

调用关闭后如何保持父 View Controller 的原始状态？

Answer 1

经过几个小时的挖掘苹果文档，我终于找到了以下解决方案，它对我有用。希望它对将来的人有所帮助。

[https://developer.apple.com/documentation/uikit/uimodalpresentationstyle/overcurrentcontext][1]

presentViewController.modalPresentationStyle = .overCurrentContext

此外，如果有选项卡栏，如果将呈现样式设置为 overCurrentContext，则 subview Controller 的底部将位于其下方。解决方法是从窗口的 rootViewController 中呈现 subview Controller 。

sender.view.window?.rootViewController?.present(viewController, animated: true, completion: nil)

现在，当调用解除时，viewWillAppear 不会被触发，我可以保留父 View Controller 的数据及其状态。