应用程序在 iOS 12.0 中崩溃

Question

应用程序在iOS 12.0之前在iOS 12.0中崩溃，它工作正常，我已经用谷歌搜索了它，但没有为下面的崩溃日志找到任何解决方案。

由于未捕获的异常"NSUnknownKeyException"而终止应用，原因："[ setValue：forUndefinedKey：]：此类不符合键值编码的键值编码，因为键应该始终警报而应用是前景。

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，shouldAlwaysAlertWhileAppIsForegroundkeyPath 被删除，不再受支持。

---

要在 iOS12 上实现此目的：

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
}
}