从NSdate中分别获取年月日时分秒

-(NSString *)getDayWeek:(int)dayDelay{

NSString *weekDay;

NSDate *dateNow;

dateNow=[NSDate dateWithTimeIntervalSinceNow:dayDelay*24*60*60];//dayDelay代表向后推几天，如果是0则代表是今天，如果是1就代表向后推24小时，如果想向后推12小时，就可以改成dayDelay*12*60*60,让dayDelay＝1

NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];//设置成中国阳历

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

NSInteger unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSWeekdayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;//这句我也不明白具体时用来做什么。。。

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

long weekNumber = [comps weekday]; //获取星期对应的长整形字符串

long day=[comps day];//获取日期对应的长整形字符串

long year=[comps year];//获取年对应的长整形字符串

long month=[comps month];//获取月对应的长整形字符串

long hour=[comps hour];//获取小时对应的长整形字符串

long minute=[comps minute];//获取月对应的长整形字符串

long second=[comps second];//获取秒对应的长整形字符串

NSString *riQi =[NSString stringWithFormat:@"%ld日",day];//把日期长整形转成对应的汉字字符串

switch (weekNumber) {

case 1:

weekDay=@"星期日";

break;

case 2:

weekDay=@"星期一";

break;

case 3:

weekDay=@"星期二";

break;

case 4:

weekDay=@"星期三";

break;

case 5:

weekDay=@"星期四";

break;

case 6:

weekDay=@"星期五";

break;

case 7:

weekDay=@"星期六";

break;

default:

break;

}

weekDay=[riQi stringByAppendingString:weekDay];//日期和星期

return weekDay;

}