iOS 12.0 中的应用程序崩溃

Question

应用程序在 iOS 12.0 之前的 iOS 12.0 中崩溃，它工作正常，我用谷歌搜索了它，但没有得到以下崩溃日志的任何解决方案。

由于未捕获的异常“NSUnknownKeyException”而终止应用程序，原因：“[setValue:forUndefinedKey:]：此类与键 shouldAlwaysAlertWhileAppIsForeground 的键值编码不兼容。”

let content = UNMutableNotificationContent()
//App crash on below line
content.setValue(true, forKeyPath: "shouldAlwaysAlertWhileAppIsForeground")

有人解决过此类问题吗？

Answer 1

在 iOS12 中，shouldAlwaysAlertWhileAppIsForeground keyPath 已被移除且不再受支持。

---

要在 iOS12 上实现：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    UNUserNotificationCenter.current().delegate = self
    ...
}
...
extension AppDelegate: UNUserNotificationCenterDelegate {
    // The method will be called on the delegate only if the application is in the foreground. 
    // If the method is not implemented or the handler is not called in a timely manner then the notification will not be presented. 
    // The application can choose to have the notification presented as a sound, badge, alert and/or in the notification list. 
    //This decision should be based on whether the information in the notification is otherwise visible to the user.
    func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
        completionHandler([.alert, .sound])// Will present an alert and will play a sound when a notification arrives
    }
}