IOS 10.2简单警报和徽章上的UserNotifications问题

当您的本地通知触发时,您的应用可能仍处于前台,因此您需要实施委托方法,以便通知执行任何操作.例如,在您的委托中定义此方法将允许通知显示警报,发出声音并更新徽章：

func userNotificationCenter(_ center: UNUserNotificationCenter,willPresent notification: UNNotification,withCompletionHandler completionHandler: @escaping (UNNotificationPresentationoptions) -> Void) {
    completionHandler([.alert,.badge,.sound])
}

关于徽章：

我观察到创建一个UNMutableNotificationContent对象并仅指定徽章值(作为NSNumber对象)适用于除0之外的所有徽章值(即,您无法以这种方式清除徽章).我没有找到任何关于为什么0的行为与任何其他值不同的文档,特别是因为.badge属性被定义为NSNumber？所以框架应该能够区分nil(无变化)和0(清除徽章).

我已针对此提交了radar.

作为解决方法,我发现在UNMutableNotificationContent对象上设置title属性,徽章值为NSNumber(值：0).如果缺少title属性,则不会触发.

添加title属性仍然不会向用户显示警告(更新：在iOS 11中不再是这种情况！),因此这是一种无需调用UIApplication对象即可将徽章值静默更新为0的方法(通过UIApplication.shared.applicationIconBadgeNumber = 0).

这是我的示例项目中的全部代码; ViewController代码中有一个MARK,显示插入title属性的位置可以解决问题：

//
//  AppDelegate.swift
//  userNotificationZeroBadgeTest
//
//  Created by Jeff Vautin on 1/3/17.
//  copyright © 2017 Jeff Vautin. All rights reserved.
//

import UIKit
import UserNotifications

@UIApplicationMain
class AppDelegate: UIResponder,UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication,didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

        UNUserNotificationCenter.current().requestAuthorization(options: [.badge,.alert,.sound]) { (success,error) -> Void in
            print("Badge auth: \(success)")
        }

        // For handling Foreground notifications,this needs to be assigned before finishing this method
        let vc = window?.rootViewController as! ViewController
        let center = UNUserNotificationCenter.current()
        center.delegate = vc

        return true
    }
}

//
//  ViewController.swift
//  userNotificationZeroBadgeTest
//
//  Created by Jeff Vautin on 1/3/17.
//  copyright © 2017 Jeff Vautin. All rights reserved.
//

import UIKit
import UserNotifications

class ViewController: UIViewController,UNUserNotificationCenterDelegate {

    @IBAction func start(_ sender: Any) {
        // Reset badge directly (this always works)
        UIApplication.shared.applicationIconBadgeNumber = 0


        let center = UNUserNotificationCenter.current()

        // Schedule badge value of 1 in 5 seconds
        let notificationBadgeOneContent = UNMutableNotificationContent()
        notificationBadgeOneContent.badge = NSNumber(value: 1)
        let notificationBadgeOneTrigger = UNTimeIntervalNotificationTrigger.init(timeInterval: 1*5,repeats: false)
        let notificationBadgeOneRequest = UNNotificationRequest.init(identifier: "1",content: notificationBadgeOneContent,trigger: notificationBadgeOneTrigger)
        center.add(notificationBadgeOneRequest)

        // Schedule badge value of 2 in 10 seconds
        let notificationBadgeTwoContent = UNMutableNotificationContent()
        notificationBadgeTwoContent.badge = NSNumber(value: 2)
        let notificationBadgeTwoTrigger = UNTimeIntervalNotificationTrigger.init(timeInterval: 2*5,repeats: false)
        let notificationBadgeTwoRequest = UNNotificationRequest.init(identifier: "2",content: notificationBadgeTwoContent,trigger: notificationBadgeTwoTrigger)
        center.add(notificationBadgeTwoRequest)

        // Schedule badge value of 3 in 15 seconds
        let notificationBadgeThreeContent = UNMutableNotificationContent()
        notificationBadgeThreeContent.badge = NSNumber(value: 3)
        let notificationBadgeThreeTrigger = UNTimeIntervalNotificationTrigger.init(timeInterval: 3*5,repeats: false)
        let notificationBadgeThreeRequest = UNNotificationRequest.init(identifier: "3",content: notificationBadgeThreeContent,trigger: notificationBadgeThreeTrigger)
        center.add(notificationBadgeThreeRequest)

        // Schedule badge value of 4 in 20 seconds
        let notificationBadgeFourContent = UNMutableNotificationContent()
        notificationBadgeFourContent.badge = NSNumber(value: 4)
        let notificationBadgeFourTrigger = UNTimeIntervalNotificationTrigger.init(timeInterval: 4*5,repeats: false)
        let notificationBadgeFourRequest = UNNotificationRequest.init(identifier: "4",content: notificationBadgeFourContent,trigger: notificationBadgeFourTrigger)
        center.add(notificationBadgeFourRequest)

        // Schedule badge value of 0 in 25 seconds
        let notificationBadgeZeroContent = UNMutableNotificationContent()
        // MARK: Uncommenting this line setting title property will cause notification to fire properly.
        //notificationBadgeZeroContent.title = "Zero!"
        notificationBadgeZeroContent.badge = NSNumber(value: 0)
        let notificationBadgeZeroTrigger = UNTimeIntervalNotificationTrigger.init(timeInterval: 5*5,repeats: false)
        let notificationBadgeZeroRequest = UNNotificationRequest.init(identifier: "0",content: notificationBadgeZeroContent,trigger: notificationBadgeZeroTrigger)
        center.add(notificationBadgeZeroRequest)
    }

    @IBAction func listNotifications(_ sender: Any) {
        let center = UNUserNotificationCenter.current()
        center.getDeliverednotifications() { (notificationArray) -> Void in
            print("Delivered notifications: \(notificationArray)")
        }
        center.getPendingNotificationRequests() { (notificationArray) -> Void in
            print("Pending notifications: \(notificationArray)")
        }
    }

    // MARK: UNUserNotificationCenterDelegate

    func userNotificationCenter(_ center: UNUserNotificationCenter,withCompletionHandler completionHandler: @escaping (UNNotificationPresentationoptions) -> Void) {
        print("Received notification: \(notification)")
        completionHandler([.alert,.sound])
    }
}