我想从2个时间间隔中提取按天分组的日期范围。 例如,来自:
let startDateTimeInterval: NSTimeInterval = 1462060790 // "2016-04-30 23:59:50 +0000\n"
let endDateTimeInterval: NSTimeInterval = 1462183200 // "2016-05-02 00:00:10 +0000\n"
我想得到:
9 seconds // "[2016-04-30 23:59:50 => 2016-04-30 23:59:59]
86399 seconds // "[2016-05-01 00:00:00 => 2016-05-01 23:59:59]
10 seconds // "[2016-05-02 00:00:00 => 2016-05-01 00:09:59]
我完成了它,但我想知道是否有更好的解决方案。 我的方法是:
1- Create NSDate from startDateTimeInterval
2- Create NSDate for end of day (23:59:59) from startDate (previous step)
3- Get difference between these 2 dates.
4- increment startDateTimeInterval with difference in seconds (previous step) and go back to step 1 with updated startDateTimeInterval.
Repeat steps while startDate < endDate
这是我的代码:
func createItemsPerDay(startDateTimeInterval: NSTimeInterval, endDateTimeInterval: NSTimeInterval)
{
var currentTimeInterval = startDateTimeInterval
let currentDate = NSDate(timeIntervalSince1970: currentTimeInterval)
var currentDateEndOfDay = currentDate.endOfDay(NSTimeZone(forSecondsFromGMT: 0))
if (currentDateEndOfDay.timeIntervalSince1970 > endDateTimeInterval) {
currentDateEndOfDay = NSDate(timeIntervalSince1970: endDateTimeInterval)
}
let numberOfElapsedSecondsForEvent = currentDateEndOfDay.timeIntervalSinceDate(currentDate)
print("event: \(numberOfElapsedSecondsForEvent) seconds")
currentTimeInterval += (numberOfElapsedSecondsForEvent + 1)
if (currentTimeInterval < endDateTimeInterval) {
createItemsPerDay(startDateTimeInterval: currentTimeInterval, endDateTimeInterval: endDateTimeInterval)
}
}
你有什么建议吗?
谢谢!
答案 0 :(得分:1)
我建议采用以下解决方案。
import Foundation
func timeIntervalsPerDay(start: NSDate, _ end: NSDate, calendar: NSCalendar) -> [NSTimeInterval] {
var timeIntervals = [NSTimeInterval]()
let dayStart = NSDateComponents()
dayStart.hour = 0
dayStart.minute = 0
dayStart.second = 0
var prevDate = start
calendar.enumerateDatesStartingAfterDate(start, matchingComponents: dayStart, options: [.MatchStrictly]) { date, exactMatch, _stop in
let stop = date.map { $0.compare(end) != .OrderedAscending } ?? false
if let date = date where !stop {
timeIntervals.append(date.timeIntervalSinceDate(prevDate))
prevDate = date
}
_stop.memory = ObjCBool(stop)
}
timeIntervals.append(end.timeIntervalSinceDate(prevDate))
return timeIntervals
}
let df = NSDateFormatter()
df.dateFormat = "yyyy-MM-dd HH:mm:ss Z"
let start = df.dateFromString("2016-04-30 23:59:50 +0000")!
let end = df.dateFromString("2016-05-02 00:00:10 +0000")!
let calendar = NSCalendar(identifier: NSCalendarIdentifierGregorian)!
calendar.timeZone = NSTimeZone(name: "UTC")!
print(timeIntervalsPerDay(start, end, calendar: calendar)) // [10.0, 86400.0, 10.0]
使用NSCalendar
是一种更可靠的方法,然后直接在NSTimeInterval
上运行,因为日历会计算一些异常情况,例如闰秒等。