IOS 获取年月日、星期

#pragma mark - 获取年月日及星期+ (NSString *)stringFromDate{    // 添加日期        NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];    NSDateComponents *comps = [[NSDateComponents alloc] init];    NSInteger unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSWeekdayCalendarUnit |    NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;        NSDate *  senddate=[NSDate date];    NSDateFormatter  *dateformatter=[[NSDateFormatter alloc] init];    [dateformatter setDateFormat:@"YYYY-MM-dd"];    comps = [calendar components:unitFlags fromDate:senddate];    NSString *locationString=[dateformatter stringFromDate:senddate];    NSString *date_weekStr = [NSString stringWithFormat:@"%@ %@",locationString,[self week:[comps weekday]]];    return date_weekStr;}#pragma mark - 推算星期+(NSString *)week:(NSInteger)week{    NSString *weekStr=nil;    if(week==1)    {        weekStr=@"星期天";    }else if(week==2){        weekStr=@"星期一";            }else if(week==3){        weekStr=@"星期二";            }else if(week==4){        weekStr=@"星期三";            }else if(week==5){        weekStr=@"星期四";            }else if(week==6){        weekStr=@"星期五";            }else if(week==7){        weekStr=@"星期六";            }    return weekStr;}