Question

首先说

'UIApplicationDidEnterBackground'已重命名为 'UIApplication.didEnterBackgroundNotification'

当我点它时说

类型'Notification.Name'（aka'NSNotification.Name'）没有成员 'UIApplication'

func listenForBackgroundNotification() {
    observer = NotificationCenter.default.addObserver(forName: Notification.Name.UIApplicationDidEnterBackground, object: nil, queue: OperationQueue.main) { [weak self] _ in
        if let weakSelf = self {
            if weakSelf.presentedViewController != nil {
                weakSelf.dismiss(animated: true, completion: nil)
            }
            weakSelf.descriptionTextView.resignFirstResponder()

        }
    }
}

Answer 1

更改

random_state

到

forName: Notification.Name.UIApplicationDidEnterBackground

Answer 2

类型为“ NSNotification”的错误在swift4.2中没有成员“ UIApplication”

NotificationCenter.default.addObserver(self, selector:#selector(handleNotification), name: NSNotification.Name.UIApplicationDidEnterBackground, object: nil)

需要相应地更改

NotificationCenter.default.addObserver(self, selector:#selector(handleNotification), name: UIApplication.didEnterBackgroundNotification, object: nil)

Answer 3

Xcode 11.4.1，Swift 5

有完全相同的问题。我的问题是我没有在自定义类中导入UIKit

import UIKit

然后，我能够实现以下目标：

name: UIApplication.didEnterBackgroundNotification

Answer 4

Xcode 11，快捷键5

UIApplication.didBecomeActiveNotification

Answer 5

如果UIApplicaiton.didEnterBackgroundNotificaiton不起作用，请尝试.UIApplicationDidEnterBackground。

Answer 6

类似错误onSwap: () { if (OrientationSingleton.left) { OrientationSingleton.left = false; SystemChrome.setPreferredOrientations([DeviceOrientation.landscapeRight]); } else { OrientationSingleton.left = true; SystemChrome.setPreferredOrientations([DeviceOrientation.landscapeLeft]); } }

要解决 Swift 5

中的此错误

您应该更改通话方式：

'UIApplicationDidChangeStatusBarOrientation' has been renamed to 'UIApplication.didChangeStatusBarOrientationNotification'

收件人

NotificationCenter.default.addObserver(self, selector: #selector(self.configureActivityIndicatorPosition), name: .UIApplicationDidChangeStatusBarOrientation, object: nil)

类型“ Notification.Name”（又名“ NSNotification.Name”）没有成员“ UIApplication”

6 个答案: