推送通知中能否嵌入倒计时计时器？求非SwiftUI实现方法

完全可以不使用SwiftUI实现这类带倒计时的推送通知，依托UIKit框架结合UserNotifications就能实现和示例图一致的效果，具体实现步骤如下：

1. 申请推送通知权限 #

首先需要向用户申请推送通知权限，尤其是时间敏感通知权限（确保倒计时通知能及时展示并更新）：

import UserNotifications

func requestNotificationPermissions() {
    let center = UNUserNotificationCenter.current()
    center.requestAuthorization(options: [.alert, .sound, .badge, .timeSensitive]) { granted, error in
        if let error = error {
            print("权限申请失败: \(error.localizedDescription)")
        }
    }
}

2. 创建本地倒计时通知（含实时更新逻辑） #

要实现动态倒计时效果，需要借助Notification Service Extension来实时更新通知内容，具体操作如下：

步骤1：添加Notification Service Extension #

在Xcode中通过File > New > Target > Notification Service Extension添加扩展，用于后续实时更新倒计时文本。

步骤2：主App中创建初始通知 #

import UserNotifications

func scheduleCountdownNotification(endTime: Date) {
    let content = UNMutableNotificationContent()
    content.title = "活动倒计时"
    content.body = "距离结束还有"
    content.categoryIdentifier = "CountdownNotification"
    content.interruptionLevel = .timeSensitive
    // 将结束时间存入userInfo，供扩展计算剩余时间
    content.userInfo = ["endTime": endTime.timeIntervalSince1970]
    
    // 立即触发通知，后续由扩展循环更新内容
    let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 1, repeats: false)
    let request = UNNotificationRequest(identifier: UUID().uuidString, content: content, trigger: trigger)
    
    UNUserNotificationCenter.current().add(request) { error in
        if let error = error {
            print("通知创建失败: \(error.localizedDescription)")
        }
    }
}

步骤3：扩展中实时更新倒计时 #

在Notification Service Extension的didReceive(_:withContentHandler:)方法中计算剩余时间并更新通知内容：

import UserNotifications

class NotificationService: UNNotificationServiceExtension {

    var contentHandler: ((UNNotificationContent) -> Void)?
    var bestAttemptContent: UNMutableNotificationContent?

    override func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler: @escaping (UNNotificationContent) -> Void) {
        self.contentHandler = contentHandler
        bestAttemptContent = (request.content.mutableCopy() as? UNMutableNotificationContent)
        
        if let bestAttemptContent = bestAttemptContent,
           let endTimeInterval = bestAttemptContent.userInfo["endTime"] as? TimeInterval {
            let endTime = Date(timeIntervalSince1970: endTimeInterval)
            let currentTime = Date()
            let timeLeft = endTime.timeIntervalSince(currentTime)
            
            if timeLeft > 0 {
                let hours = Int(timeLeft) / 3600
                let minutes = (Int(timeLeft) % 3600) / 60
                let seconds = Int(timeLeft) % 60
                bestAttemptContent.body = String(format: "距离结束还有 %02d:%02d:%02d", hours, minutes, seconds)
                // 每隔1秒重新调度通知，实现倒计时实时刷新
                if timeLeft > 1 {
                    let updateTrigger = UNTimeIntervalNotificationTrigger(timeInterval: 1, repeats: false)
                    let updateRequest = UNNotificationRequest(identifier: request.identifier, content: bestAttemptContent, trigger: updateTrigger)
                    UNUserNotificationCenter.current().add(updateRequest)
                }
            } else {
                bestAttemptContent.body = "活动已结束"
            }
        }
        
        contentHandler(bestAttemptContent ?? request.content)
    }

    override func serviceExtensionTimeWillExpire() {
        // 超时 fallback 处理
        if let contentHandler = contentHandler, let bestAttemptContent = bestAttemptContent {
            contentHandler(bestAttemptContent)
        }
    }
}

3. 配置通知类别（可选） #

如果需要给倒计时通知添加自定义操作按钮，可以提前配置通知类别：

func setupNotificationCategories() {
    let center = UNUserNotificationCenter.current()
    let category = UNNotificationCategory(identifier: "CountdownNotification", actions: [], intentIdentifiers: [], options: [])
    center.setNotificationCategories([category])
}

注意事项 #

• 该方案支持iOS 15及以上系统，需确保项目部署版本符合要求
• 通知扩展需单独配置签名和权限，避免打包出错
• 若使用远程推送，需在服务端推送的payload中携带倒计时结束时间，再由扩展处理更新

内容的提问来源于stack exchange，提问作者Ahmed Sokar