iPhone开发 获取系统时间 星期 年 月 日 时 分 秒

//获取系统当前时间

    

    - (NSString*)get_system_today_time

    {

        NSDate *date = [NSDate date];

        NSDateFormatter *formatter = [[NSDateFormatter alloc] init];

        [formatter setDateStyle:kCFDateFormatterMediumStyle];

        [formatter setTimeStyle:kCFDateFormatterShortStyle];

        [formatter setDateFormat:@"YYYY-MM-dd-hh-mm-ss"];

        NSString *string_time = [formatterstringFromDate:date];

        NSArray *time = [string_timecomponentsSeparatedByString:@"-"];

        int value_year = [[timeobjectAtIndex:0]intValue];

        int value_month = [[timeobjectAtIndex:1]intValue];

        int value_day = [[timeobjectAtIndex:2]intValue];

        int value_hour = [[timeobjectAtIndex:3]intValue];

        int value_minute = [[timeobjectAtIndex:4]intValue];

        int value_second = [[timeobjectAtIndex:5]intValue];

        [formatter setDateFormat:@"EEEE"];

        NSString *week_day = [formatter stringFromDate:date];

        [formatter release];

       NSString *system_time = [[NSStringalloc]initWithFormat:@"{\"year\":\"%d\",\"month\":\"%d\",\"day\":\"%d\",\"hour\":\"%d\",\"minute\":\"%d\",\"second\":\"%d\",\"week_day\":\"%@\"}",value_year,value_month,value_day,value_hour,value_minute,value_second,week_day];

        NSLog(@"\nsystem time is %@",system_time);

        return [system_timeautorelease];

    }

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NSDate *date = [NSDate date];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *comps;

// 年月日获得
comps = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit) 
                                        fromDate:date];
NSInteger year = [comps year];
NSInteger month = [comps month];
NSInteger day = [comps day];
NSLog(@"year: %d month: %d, day: %d", year, month, day);


//当前的时分秒获得
comps = [calendar components:(NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit)
                                        fromDate:date];
NSInteger hour = [comps hour];
NSInteger minute = [comps minute];
NSInteger second = [comps second];
NSLog(@"hour: %d minute: %d second: %d", hour, minute, second);

// 周几和星期几获得
comps = [calendar components:(NSWeekCalendarUnit | NSWeekdayCalendarUnit | NSWeekdayOrdinalCalendarUnit)
                                        fromDate:date];
NSInteger week = [comps week]; // 今年的第几周
NSInteger weekday = [comps weekday]; // 星期几（注意，周日是“1”，周一是“2”。。。。）
NSInteger weekdayOrdinal = [comps weekdayOrdinal]; // 这个月的第几周
NSLog(@"week: %d weekday: %d weekday ordinal: %d", week, weekday, weekdayOrdinal);