每 n 天安排一次本地通知时区安全

问题描述

我相信这已经被问过几次了，但没有明确的答案。

有两种方法可以安排临时通知：UNCalendarNotification 和 UNTimeIntervalNotificationTrigger。

为特定时间和一周中的某天安排通知是微不足道的，与在该月的特定日期安排相同，但安排在特定时间，每 n 天不是那么简单。

例如每 5 天 11:00。

UNTimeIntervalNotificationTrigger 似乎是合适的类，除非在夏令时或时区发生变化时会出现问题。例如。夏令时结束，现在您的通知时间为 10:00，而不是 11:00。

DateComponents 类上的 day 属性与 UNCalendarNotification 类一起可能包含解决方案，因为它在文档中说“一天或天数”。我将其解释为“一个月中的特定日期（一天）或 n 天数（天数）”。

深入研究 day property docs，它读到“这个值是在使用它的日历的上下文中解释的”。

如何将 day 属性与日历的上下文一起使用来处理天数而不是一个月中的特定天数？

此外，hour 中 minute 和 DateComponents 属性的文档还分别显示为“一小时或数小时”和“一分钟或分钟数”。因此，即使您将 day 设置为“天数”，您如何正确设置 hour 和 minute？

很明显，此功能在 iOS 中是可行的 - 提醒应用就是证明。

解决方法

您可以使用 UNCalendarNotificationTrigger 预先设置 n 次，并使用当前时区的调整日历

import SwiftUI

class NotificationManager: NSObject,UNUserNotificationCenterDelegate{
    static let shared: NotificationManager = NotificationManager()
    let notificationCenter = UNUserNotificationCenter.current()
    
    private override init(){
        super.init()
        requestNotification()
        notificationCenter.delegate = self
        getnotifications()
    }
    
    func requestNotification() {
        print(#function)
        notificationCenter.requestAuthorization(options: [.alert,.sound,.badge]) { granted,error in
            
            if let error = error {
                // Handle the error here.
                print(error)
            }
            
            // Enable or disable features based on the authorization.
        }
    }
    /// Uses [.day,.hour,.minute,.second] in current timeZone
    func scheduleCalendarNotification(title: String,body: String,date: Date,repeats: Bool = false,identifier: String) {
        print(#function)
        
        let content = UNMutableNotificationContent()
        content.title = title
        content.body = body
        
        let calendar = NSCalendar.current

        let components = calendar.dateComponents([.day,.second],from: date.addingTimeInterval(TimeInterval(TimeZone.current.secondsFromGMT())))
        
        let trigger = UNCalendarNotificationTrigger(dateMatching: components,repeats: repeats)
        
        let request = UNNotificationRequest(identifier: identifier,content: content,trigger: trigger)
        notificationCenter.add(request) { (error) in
            if error != nil {
                print(error!)
            }
        }
    }
    ///Sets up multiple calendar notification based on a date
    func recurringNotification(title: String,identifier: String,everyXDays: Int,count: Int){
        print(#function)
        for n in 0..<count{
            print(n)
            let newDate = date.addingTimeInterval(TimeInterval(60*60*24*everyXDays*n))
            //Idenfier must be unique so I added the n
            scheduleCalendarNotification(title: title,body: body,date: newDate,identifier: identifier + n.description)
            print(newDate)
        }
    }
    ///Prints to console schduled notifications
    func getnotifications(){
        notificationCenter.getPendingNotificationRequests { request in
            for req in request{
                if req.trigger is UNCalendarNotificationTrigger{
                    print((req.trigger as! UNCalendarNotificationTrigger).nextTriggerDate()?.description ?? "invalid next trigger date")
                }
            }
        }
    }
    
    func userNotificationCenter(_ center: UNUserNotificationCenter,willPresent notification: UNNotification,withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
        
        completionHandler(.banner)
    }
}
class ZuluNotTriggerViewModel:NSObject,ObservableObject,UNUserNotificationCenterDelegate{
    @Published var currentTime: Date = Date()
    let notificationMgr = NotificationManager.shared
    
    
    ///Sets up multiple calendar notification based on a date
    func recurringNotification(title: String,count: Int){
        print(#function)
        notificationMgr.recurringNotification(title: title,date: date,identifier: identifier,everyXDays: everyXDays,count: count)
        
        //just for show now so you can see the current date in ui
        self.currentTime = Date()
    }
    ///Prints to console schduled notifications
    func getnotifications(){
        notificationMgr.getnotifications()
    }
    
}
struct ZuluNotTriggerView: View {
    @StateObject var vm: ZuluNotTriggerViewModel = ZuluNotTriggerViewModel()
    var body: some View {
        VStack{
            Button(vm.currentTime.description,action: {
                vm.currentTime = Date()
            })
            Button("schedule-notification",action: {
                let twoMinOffset = 120
                //first one will be in 120 seconds
                //gives time to change settings in simulator
                //initial day,hour,minute,second
                let initialDate = Date().addingTimeInterval(TimeInterval(twoMinOffset))
                //relevant components will be day,hour minutes,seconds
                vm.recurringNotification(title: "test",body: "repeat body",date: initialDate,identifier: "test",everyXDays: 2,count: 10)
            })
            
            Button("see notification",action: {
                vm.getnotifications()
            })
        }
    }
}

struct ZuluNotTriggerView_Previews: PreviewProvider {
    static var previews: some View {
        ZuluNotTriggerView()
    }
}