这是我给斯威夫特用的

var date = NSDate()
let currentTime = Int64(date.timeIntervalSince1970 * 1000)

print("Time in milliseconds is \(currentTime)")

使用本网站验证准确性http://currentmillis.com/

CFAbsoluteTimeGetCurrent ()

Absolute time is measured in seconds relative to the absolute reference date of Jan 1 2001 00:00:00 GMT. A positive value represents a date after the reference date, a negative value represents a date before it. For example, the absolute time -32940326 is equivalent to December 16th, 1999 at 17:54:34. Repeated calls to this function do not guarantee monotonically increasing results. The system time may decrease due to synchronization with external time references or due to an explicit user change of the clock.

我需要一个NSNumber对象，包含[[NSDate date] timeIntervalSince1970]的确切结果。因为这个函数被调用了很多次，我并不真的需要创建一个NSDate对象，性能不是很好。

所以要得到原始函数给我的格式，试试这个:

#include <sys/time.h>
struct timeval tv;
gettimeofday(&tv,NULL);
double perciseTimeStamp = tv.tv_sec + tv.tv_usec * 0.000001;

这应该给你完全相同的结果[[NSDate date] timeIntervalSince1970]

斯威夫特2

let seconds = NSDate().timeIntervalSince1970
let milliseconds = seconds * 1000.0

斯威夫特3

let currentTimeInMiliseconds = Date().timeIntervalSince1970.milliseconds

在Swift中，我们可以创建一个函数，并如下所示

func getCurrentMillis()->Int64{
    return  Int64(NSDate().timeIntervalSince1970 * 1000)
}

var currentTime = getCurrentMillis()

虽然它在Swift 3.0中工作得很好，但我们可以修改和使用Date类而不是3.0中的NSDate

斯威夫特3.0

func getCurrentMillis()->Int64 {
    return Int64(Date().timeIntervalSince1970 * 1000)
}

var currentTime = getCurrentMillis()

如果你不想包含Quartz框架，[NSDate timeintervalsincerely eferencedate]是另一个选项。它返回一个double，表示秒数。