ios 开发中获得当前时间的 年月日，时分秒

NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

NSDate *now;

NSDateComponents *comps = [[NSDateComponents alloc] init];

NSInteger unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSWeekdayCalendarUnit |

NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;

now=[NSDate date];

comps = [calendar components:unitFlags fromDate:now];

week = [comps weekday];

month = [comps month];

day = [comps day];

hour = [comps hour];

min = [comps minute];

sec = [comps second];

//Week:

1 －－星期天

2－－星期一

3－－星期二

4－－星期三

5－－星期四

6－－星期五

7－－星期六