NSString与NSDate互相转换

转载地址 http://blog.sina.com.cn/s/blog_6d01cce3010199if.html

由NSDate 转换为NSString:

1. NSDateFormatter*dateFormatter = [[NSDateFormatter alloc] init];
2. [dateFormattersetDateFormat:@"yyyy-MM-dd HH:mm:ss"];
3. NSString*strDate = [dateFormatter stringFromDate:[NSDatedate]];
4. NSLog(@"%@",strDate);
5. [dateFormatterrelease];

结果:

1. 2010-08-0416:01:03

由NSString 转换为NSDate:

1. NSDateFormatter*dateFormatter = [[NSDateFormatter alloc] init];
2. [dateFormattersetDateFormat:@"yyyy-MM-dd HH:mm:ss"];
3. NSDate *date =[dateFormatter dateFromString:@"2010-08-04 16:01:03"];
4. NSLog(@"%@",date);
5. [dateFormatterrelease];

结果:

1. 2010-08-0416:01:03 +0800

日期之间比较可用以下方法

    -(BOOL)isEqualToDate:(NSDate *)otherDate;

    与otherDate比较，相同返回YES

 

    - (NSDate*)earlierDate:(NSDate *)anotherDate;

    与anotherDate比较，返回较早的那个日期

 

    - (NSDate*)laterDate:(NSDate *)anotherDate;

    与anotherDate比较，返回较晚的那个日期

 

    -(NSComparisonResult)compare:(NSDate *)other;

   该方法用于排序时调用:

     . 当实例保存的日期值与anotherDate相同时返回NSOrderedSame

     . 当实例保存的日期值晚于anotherDate时返回NSOrderedDescending

     . 当实例保存的日期值早于anotherDate时返回NSOrderedAscending