日期以毫秒为单位并在Swift中返回日期

小编典典

日期以毫秒为单位并在Swift中返回日期

swift

我将当前时间（UTC）以纳秒为单位，然后需要以纳秒为单位，然后返回本地时间。我能够将时间缩短到十亿分之一秒，然后再返回到日期字符串，但是当我从字符串转到日期时，时间变得很复杂。

    //Date to milliseconds
     func currentTimeInMiliseconds() -> Int! {
            let currentDate = NSDate()
            let dateFormatter = DateFormatter()
            dateFormatter.dateFormat = format
            dateFormatter.timeZone = NSTimeZone(name: "UTC") as TimeZone!
            let date = dateFormatter.date(from: dateFormatter.string(from: currentDate as Date))
            let nowDouble = date!.timeIntervalSince1970
            return Int(nowDouble*1000)
        }

    //Milliseconds to date
    extension Int {
        func dateFromMilliseconds(format:String) -> Date {
            let date : NSDate! = NSDate(timeIntervalSince1970:Double(self) / 1000.0)
            let dateFormatter = DateFormatter()
            dateFormatter.dateFormat = format
            dateFormatter.timeZone = TimeZone.current
            let timeStamp = dateFormatter.string(from: date as Date)

let formatter = DateFormatter()
            formatter.dateFormat = format
            return ( formatter.date( from: timeStamp ) )!
        }
    }

//时间戳正确，但返回的日期不正确

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2020-07-07

共1个答案

小编典典

我不明白您为什么要对字符串做任何事情…

extension Date {
    var millisecondsSince1970:Int64 {
        return Int64((self.timeIntervalSince1970 * 1000.0).rounded())
    }

    init(milliseconds:Int64) {
        self = Date(timeIntervalSince1970: TimeInterval(milliseconds) / 1000)
    }
}


Date().millisecondsSince1970 // 1476889390939
Date(milliseconds: 0) // "Dec 31, 1969, 4:00 PM" (PDT variant of 1970 UTC)

2020-07-07