如何在指定日期前2天触发UserNotifications

import UserNotifications

// 请求用户授权
UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { (granted, error) in
    if granted {
        // 创建通知内容
        let content = UNMutableNotificationContent()
        content.title = "重要提醒"
        content.body = "您有一个重要事件将在2天后到期，请及时处理！"
        content.sound = UNNotificationSound.default
        
        // 创建触发器
        var dateComponents = DateComponents()
        dateComponents.day = -2 // 在指定日期前2天触发通知
        let trigger = UNCalendarNotificationTrigger(dateMatching: dateComponents, repeats: false)
        
        // 创建通知请求
        let request = UNNotificationRequest(identifier: "reminder", content: content, trigger: trigger)
        
        // 将通知请求添加到通知中心
        UNUserNotificationCenter.current().add(request) { (error) in
            if let error = error {
                print("添加通知请求失败：\(error.localizedDescription)")
            }
        }
    } else {
        print("用户未授权发送通知")
    }
}