将NSTimeInterval转换为NSData，然后再转换为NSTimeInterval

Question

如何将NSTimeInterval值转换为NSData

Answer 1

您也可以使用NSKeyedArchiver

    let time = NSTimeInterval(100)

    let archivedTime = NSKeyedArchiver.archivedDataWithRootObject(time)
    let unarchivedTime = NSKeyedUnarchiver.unarchiveObjectWithData(archivedTime) as! NSTimeInterval

Answer 2

Xcode 8.3.1·Swift 3.1

var nowInterval = Date().timeIntervalSince1970                                  // 1491800604.362141
let data = Data(bytes: &nowInterval, count: MemoryLayout<TimeInterval>.size)    // 8 bytes
let timeInterval: Double = data.withUnsafeBytes{ $0.pointee }

let date = Date(timeIntervalSince1970: timeInterval)   // Apr 10, 2017, 2:03 AM"

Answer 3

NSTimeInterval只是Double的一个类型。您可以像复制其他任何Foundation类型一样，通过复制字节来存档它。

var time = NSTimeInterval(100) // 100.0

let timeData = NSData(bytes: &time, length: sizeof(NSTimeInterval))

var unarchivedTime = NSTimeInterval() // You need to initialize an empty NSTimeInterval object as a var in order to mutate it

timeData.getBytes(&unarchivedTime, length: sizeof(NSTimeInterval))

print(unarchivedTime) // 100.0