獲取當前日期時間、日期時間格式化及轉換

轉自：http://blog.csdn.net/ooppookid/article/details/42506957

1.獲取當前日期時間

var nowDate = NSDate()  
var formatter = NSDateFormatter()  
formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"  
var dateString = formatter.stringFromDate(nowDate)  
println(dateString)  

2.字符串轉換日期時間

var dateString1 = "2014-1-7"  
var formatter1 = NSDateFormatter()  
formatter1.dateFormat = "yyyy-M-d"  
var date1 = formatter1.dateFromString(dateString1)  
println(date1)  

3.日期時間轉換字符串

var date2 = NSDate()  
var formatter2 = NSDateFormatter()  
formatter2.dateFormat = "yyyy-MM-dd"  
var dateString2 = formatter2.stringFromDate(date2)  
println(dateString2)