斯威夫特2

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

斯威夫特3

let currentTimeInMiliseconds = Date().timeIntervalSince1970.milliseconds

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.

// Timestamp after converting to milliseconds.

NSString * timeInMS = [NSString stringWithFormat:@"%lld", [@(floor([date timeIntervalSince1970] * 1000)) longLongValue]];

获取当前日期的毫秒数。

斯威夫特4 +:

func currentTimeInMilliSeconds()-> Int
    {
        let currentDate = Date()
        let since1970 = currentDate.timeIntervalSince1970
        return Int(since1970 * 1000)
    }

[[NSDate date] timeIntervalSince1970];

它以双精度返回自epoch以来的秒数。我几乎可以肯定你可以从小数部分访问毫秒。

It may be useful to know about CodeTimestamps, which provide a wrapper around mach-based timing functions. This gives you nanosecond-resolution timing data - 1000000x more precise than milliseconds. Yes, a million times more precise. (The prefixes are milli, micro, nano, each 1000x more precise than the last.) Even if you don't need CodeTimestamps, check out the code (it's open source) to see how they use mach to get the timing data. This would be useful when you need more precision and want a faster method call than the NSDate approach.

http://eng.pulse.me/line-by-line-speed-analysis-for-ios-apps/