如何将NSString转换为NSDate？

Question

如何转换NSString至NSDate ？

它必须在YYYY-MM-DD HH：MM：SS，当它从的NSString转换成的NSDate格式这种格式

Answer 1

使用NSDateFormatter的dateFromString：

NSString *dateStr = @"20100212"; 

// Convert string to date object 
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init]; 
[dateFormat setDateFormat:@"yyyyMMdd"]; 
NSDate *date = [dateFormat dateFromString:dateStr]; 

// Convert date object to desired output format 
[dateFormat setDateFormat:@"YYYY-MM-dd HH:mm:ss"]; 
dateStr = [dateFormat stringFromDate:date]; 
[dateFormat release]; 

Answer 2

为了进一步参考。退房：

http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/DataFormatting/Articles/dfDateFormatting10_4.html#//apple_ref/doc/uid/TP40002369-SW1

Answer 3

做出了的NSString扩展了点。

// Simple as this. 
date = dateString.dateValue; 

由于NSDataDetector，它承认了一大堆格式。

// Tested in GMT+1 (Hungary). 
@"2014-01-16" dateValue is <2014-01-16 11:00:00 +0000> 
@"2014.01.16" dateValue is <2014-01-16 11:00:00 +0000> 
@"2014/01/16" dateValue is <2014-01-16 11:00:00 +0000> 
@"2014 Jan 16" dateValue is <2014-01-16 11:00:00 +0000> 
@"2014 Jan 16th" dateValue is <2014-01-16 11:00:00 +0000> 
@"20140116" dateValue is <2014-01-16 11:00:00 +0000> 
@"01-16-2014" dateValue is <2014-01-16 11:00:00 +0000> 
@"01.16.2014" dateValue is <2014-01-16 11:00:00 +0000> 
@"01/16/2014" dateValue is <2014-01-16 11:00:00 +0000> 
@"16 January 2014" dateValue is <2014-01-16 11:00:00 +0000> 
@"01-16-2014 17:05:05" dateValue is <2014-01-16 16:05:05 +0000> 
@"01-16-2014 T 17:05:05 UTC" dateValue is <2014-01-16 17:05:05 +0000> 
@"17:05, 1 January 2014 (UTC)" dateValue is <2014-01-01 16:05:00 +0000> 

的eppz!kit部分，从GitHub抢类别NSString+EPPZKit.h。