有关在 Swift 中等待批准的计划通知的问题

Question

我创建了一个功能，可以在您设置的特定时间和一周中的某一天发出闹钟。

func scheduleNotification() {
​
let center = UNUserNotificationCenter.current()
​   let hour = 6
​   let minute = 40
​   let weekdays = [2,3,4] // mon, tue, wed
​   let content = UNMutableNotificationContent()
​
content.title = "Fire!!"
content.body = "test.!"
content.badge = 1
content.categoryIdentifier = "alarm"
content.userInfo = ["customData": "fizzbuzz"]
content.sound = UNNotificationSound.default
​
for weekday in weekdays {
var dateComponents = DateComponents()
dateComponents.hour = hour
dateComponents.minute = minute
dateComponents.weekday = weekday
let trigger = UNCalendarNotificationTrigger.init(dateMatching: dateComponents, repeats: true)
let request = UNNotificationRequest(identifier: UUID().uuidString, content: content, trigger: trigger)
center.add(request)
center.getPendingNotificationRequests { (requests) in
for request in requests {
print("trigger : (request.trigger)")
}
}
UNUserNotificationCenter.current().add(request) { (error) in
}
}
}

正如您在上面的代码中看到的，您要重复的日子是星期一、星期二和星期三。

weekdays = [2,3,4]

之后，我想使用 [2,3,4] 数组上的 for 语句创建一个在星期一、星期二和星期三响起的闹钟。

但是闹钟并没有像我想要的那样响起。

我使用 getPendingNotificationRequests 方法将计划警报列表打印到控制台。

trigger : Optional(<UNCalendarNotificationTrigger: 0x283242f20; dateComponents: <NSDateComponents: 0x2830567a0> {
Hour: 6
Minute: 40
Weekday: 2, repeats: YES>)
trigger : Optional(<UNCalendarNotificationTrigger: 0x283241920; dateComponents: <NSDateComponents: 0x283056900> {
Hour: 6
Minute: 40
Weekday: 2, repeats: YES>)
trigger : Optional(<UNCalendarNotificationTrigger: 0x2832416a0; dateComponents: <NSDateComponents: 0x2830556f0> {
Hour: 6
Minute: 40
Weekday: 3, repeats: YES>)
trigger : Optional(<UNCalendarNotificationTrigger: 0x283242f20; dateComponents: <NSDateComponents: 0x283056900> {
Hour: 6
Minute: 40
Weekday: 2, repeats: YES>)
trigger : Optional(<UNCalendarNotificationTrigger: 0x2832426e0; dateComponents: <NSDateComponents: 0x283054c40> {
Hour: 6
Minute: 40
Weekday: 3, repeats: YES>)
trigger : Optional(<UNCalendarNotificationTrigger: 0x2832413c0; dateComponents: <NSDateComponents: 0x283056930> {
Hour: 6
Minute: 40
Weekday: 4, repeats: YES>)

我想要的是三个触发器，Weekday 一个接一个地存储在 [2,3,4] 数组中。

但是，创建了六个触发器，并且工作日的顺序存储不正确。

我想问两个问题。

1. 如果你看一下上面代码的日志，如果你有一系列触发器，Weekday 存储为 2，它们是否一个接一个地执行？例如，如果是星期一，今天响一次，下周一响一次？

2. 为什么警报存储如此错误，我该如何解决这个问题？

Answer 1

你得到六个触发器的原因是，在你的 for 循环 (for weekday in weekdays(，你在每个触发器中添加两次。每个触发器在行center.add(request)处添加一次，在行UNUserNotificationCenter.current().add(request) { (error) in处再次添加。您可以通过将 for 循环更新为如下所示来解决此问题：

for weekday in weekdays {
var dateComponents = DateComponents()
dateComponents.hour = hour
dateComponents.minute = minute
dateComponents.weekday = weekday
let trigger = UNCalendarNotificationTrigger.init(dateMatching: dateComponents, repeats: true)
let request = UNNotificationRequest(identifier: UUID().uuidString, content: content, trigger: trigger)
center.current().add(request) { (error) in
if error != nil {
print(error.localizedDescription)
}
}
}

您可能还只想在 for 循环完成后打印出触发器，而不是在 for 循环中打印。所以我会在 for 循环之后添加以下代码：

func scheduleNotification() {
...
for weekday in weekdays {
...
}
//This following code was originally within your for loop, but should probably execute after the for loop instead
//The console should look a lot cleaner after doing so
center.getPendingNotificationRequests { (requests) in
for request in requests {
print("trigger : (request.trigger)")
}
}
}