swift中怎么取现在时间

var date = NSDate()
var timeFormatter = NSDateFormatter()
timeFormatter.dateFormat = "yyy-MM-dd 'at' HH:mm:ss.SSS" (格式可俺按自己需求修整)
var strNowTime = timeFormatter.stringFromDate(date) as String

var date:NSDate = NSCalendarDate.date()
var formatter:NSDateFormatter = NSDateFormatter()
formatter.dateFormat = "yyyyMMddHHmmss"
var dateString = formatter.stringFromDate(date)
println(dateString)

let dateFormatter:NSDateFormatter = NSDateFormatter();

dateFormatter.dateFormat = "yyyyMMddHHmmss";
let dateString:String = dateFormatter.stringFromDate(NSDate())