UserNotification未显示(iOS 10)

UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { (granted, error) in
    // 处理授权结果
}

let content = UNMutableNotificationContent()
content.title = "通知标题"
content.subtitle = "通知副标题"
content.body = "通知正文"

let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 5, repeats: false)

let request = UNNotificationRequest(identifier: "notificationIdentifier", content: content, trigger: trigger)
UNUserNotificationCenter.current().add(request) { (error) in
    // 处理添加请求的结果
}

let center = UNUserNotificationCenter.current()
center.delegate = self
center.requestAuthorization(options: [.alert, .sound, .badge]) { (granted, error) in
    if granted {
        center.getNotificationSettings { (settings) in
            if settings.authorizationStatus == .authorized {
                // 设置通知中心的显示样式
                center.setNotificationCategories([category])
            }
        }
    }
}