IOS 10.2 UserNotifications 关于简单警报和角标(Badge)的问题

Question

在写这篇文章之前，我对 UserNotification Framework 进行了大量研究，它取代了 IOS 10 中的 UILocalNotification。我还按照本教程学习了有关此新功能的所有信息:http://useyourloaf.com/blog/local-notifications-with-ios-10/ .

今天我在实现如此微不足道的通知时遇到了很多麻烦，而且由于这是最近的一项新功能，我找不到任何解决方案(尤其是在 Objective-C 中)!我目前有 2 种不同的通知，一种是警报，另一种是角标(Badge)更新。

警报问题

在将我的手机从 IOS 10.1 更新到 10.2 之前，我在 Appdelegate 上发出了一个警报，只要用户手动关闭应用程序就会立即触发:

-(void)applicationWillTerminate:(UIApplication *)application {
        NSLog(@"applicationWillTerminate");

        // Notification terminate
        [self registerTerminateNotification];
}

// Notification Background terminate 
-(void) registerTerminateNotification {
    // the center
    UNUserNotificationCenter * notifCenter = [UNUserNotificationCenter currentNotificationCenter];

    // Content
    UNMutableNotificationContent *content = [UNMutableNotificationContent new];
    content.title = @"Stop";
    content.body = @"Application closed";
    content.sound = [UNNotificationSound defaultSound];
    // Trigger 
    UNTimeIntervalNotificationTrigger *trigger = [UNTimeIntervalNotificationTrigger triggerWithTimeInterval:1 repeats:NO];
    // Identifier
    NSString *identifier = @"LocalNotificationTerminate";
    // création de la requête
    UNNotificationRequest *terminateRequest = [UNNotificationRequest requestWithIdentifier:identifier content:content trigger:trigger];
    // Ajout de la requête au center
    [notifCenter addNotificationRequest:terminateRequest withCompletionHandler:^(NSError * _Nullable error) {
        if (error != nil) {
            NSLog(@"Error %@: %@",identifier,error);
        }
    }];
}

在 IOS 10.2 之前它工作得很好，当我手动关闭应用程序时，会出现一个警告。但是自从我更新到IOS 10.2之后，无缘无故什么都没有出现，我什么都没改，也看不出少了什么..

角标(Badge)问题

我也尝试(这次只在 IOS 10.2 中)在我的应用程序图标上实现角标(Badge)，效果很好，直到我试图删除它。这是执行此操作的函数:

+(void) incrementBadgeIcon {
    // only increment if application is in background 
    if ([[UIApplication sharedApplication] applicationState] == UIApplicationStateBackground){

        NSLog(@"increment badge");

        // notif center 
        UNUserNotificationCenter *notifCenter = [UNUserNotificationCenter currentNotificationCenter];

        // Content
        UNMutableNotificationContent *content = [UNMutableNotificationContent new];
        content.badge = [NSNumber numberWithInt:1];
        // Trigger 
        UNTimeIntervalNotificationTrigger *trigger = [UNTimeIntervalNotificationTrigger triggerWithTimeInterval:1 repeats:NO];
        // Identifier
        NSString *identifier = @"LocalNotificationIncrementBadge";
        // request
        UNNotificationRequest *incrementBadgeRequest = [UNNotificationRequest requestWithIdentifier:identifier content:content trigger:trigger];
        // Ajout de la requête au center
        [notifCenter addNotificationRequest:incrementBadgeRequest withCompletionHandler:^(NSError * _Nullable error) {
            if (error != nil) {
                NSLog(@"Error %@: %@",identifier,error);
            }
        }];
    }
}

现在它不会增加角标(Badge)编号，正如它的名字应该暗示的那样，但它只是将角标(Badge)编号设置为 1。文档说如果您将 content.badge 设置为 0，它会删除它，但这不起作用。我尝试使用其他数字，当我手动将其更改为“2”、“3”等时……它发生了变化，但如果我将其设置为 0，则不起作用。

此外，在我之前链接的教程中，提到了几个函数，如 getPendingNotificationRequests:completionHandler: 和 getDeliveredNotificationRequests:completionHandler:。我注意到，当我在调用 incrementBadgeIcon 后立即调用这些函数时，如果 content.badge 设置为“1”、“2”等...它会出现在待处理通知列表中。但是，当我将它设置为 0 时，它不会出现在任何地方。我在 Xcode 中没有收到任何错误和警告，而且我的应用程序角标(Badge)仍然存在。

有谁知道如何修复这两个警报？

提前致谢

PS:我也尝试过使用 removeAllPendingNotificationRequests 和 removeAllDeliveredNotifications 但都没有成功。

Answer 1

关于警报:

当您的本地通知触发时，您的应用程序可能仍在前台运行，因此您需要实现委托(delegate)方法以便通知执行任何操作。例如，在您的委托(delegate)中定义此方法将允许通知显示警报、发出声音并更新角标(Badge):

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

关于角标(Badge):

我观察到创建一个 UNMutableNotificationContent 对象并仅指定角标(Badge)值(作为 NSNumber 对象)适用于除 0 以外的所有角标(Badge)值(即，您不能以这种方式清除角标(Badge))。我还没有找到任何文档来说明为什么 0 的行为与任何其他值不同，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(清除角标(Badge))。

我已经提交了 radar反对这一点。

作为变通方法，我发现在 UNMutableNotificationContent 对象上设置 title 属性，角标(Badge)值为 NSNumber(value: 0) 会 触发。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报(更新:iOS 11 不再是这种情况!)，因此这是一种静默更新角标(Badge)值的方法0 而无需调用 UIApplication 对象(通过 UIApplication.shared.applicationIconBadgeNumber = 0)。

这是我示例项目中的全部代码； ViewController 代码中有一个 MARK，显示在何处插入 title 属性可以解决问题:

//
//  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, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
        print("Received notification: \(notification)")
        completionHandler([.alert,.badge,.sound])
    }
}