didReceiveRemoteNotification 未调用 - 为什么？

Question

我的应用和 UserNotifications 框架有问题。我有一个带有 sendNotification() 函数的主视图控制器，如下所示：

let content = UNMutableNotificationContent()
        content.title = "Water Reminder"
        content.body = "What about a glass of water?"
        content.sound = UNNotificationSound.default()

        let testTrigger = UNTimeIntervalNotificationTrigger(timeInterval: 30, repeats: false)

        let identifier = Int(arc4random_uniform(999999999))

        let request = UNNotificationRequest(identifier: "\(identifier)", content: content, trigger: testTrigger)

        center.add(request, withCompletionHandler: {
            (error) in
            if let error = error {
                print("Didn't add notification request. \(error)")
            }

        })

触发器仅用于测试。好吧，30 秒后，我收到了通知。到那时，一切都很好。问题是：当它收到提醒时，它应该调用应用程序委托中的 didReceiveRemoteNotification() 函数，但它没有。这是我的功能：

func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {

    UserDefaults.standard.set(true, forKey: "didReceiveRemoteNotification")
}

所以，我收到了通知，在didFinishLaunchingWithOptions()函数中插入了这行代码：

print("\(UserDefaults.standard.bool(forKey: "didReceiveRemoteNotification")")

它给了我错误，即使我收到了通知。这怎么可能？

在功能部分中，通知和后台获取的后台模式以及推送通知被激活。应用程序委托和视图控制器都导入了 UserNotifications，添加为 UNUserNotificationCenterDelegate 并且都有一个 center.delegate = self 代码之一。为什么它不起作用？为什么我的 didReceiveRemoteNotification() 函数没有被调用？

感谢您的帮助...

Answer 1

添加这一行。

UserDefaults.standard.synchronize()

From Apple Docs:因为这个方法是周期性自动调用的，所以只能在等不及自动同步的情况下才使用这个方法

**更新：** 对于 IOS 10 使用 UserNotifications framework

(1) 导入 UserNotifications 框架

(2) 在AppDelegate.swift中添加协议UNUserNotificationCenterDelegate

(3) 在didFinishLaunchingWithOptions 启用/禁用功能

let notificationCenter = UNUserNotificationCenter.current()
notificationCenter.requestAuthorization(options:[.badge, .alert, .sound]) { (granted, error) in

}
application.registerForRemoteNotifications()

(4) 用于设备令牌

func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {

    let deviceTokenAsString = deviceToken.reduce("", {$0 + String(format: "%02X", $1)})
    print(deviceTokenAsString)


}

(5) 如果出错

func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {

        print(error)
}

如果收到通知，应该调用的委托是：

func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {

    completionHandler(UIBackgroundFetchResult.noData)

UserDefaults.standard.set(true, forKey: "didReceiveRemoteNotification")
UserDefaults.standard.synchronize()


}