今天博主有一个时间戳的需求,遇到了一些困难点,在此和大家分享,希望能够共同进步.
iOS开发中,我们在很多情况下都会遇到使用当下时间作为参数的情况,这称之为时间戳.在iOSSDK中,与时间戳相关的API主要有三个,NSDate,NSCalendar和NSDate?Components.
NSDate 就是一个绝对的时间，可以换算成相对1970s的时差.
NSCalendar 顾名思义就是日历，封装了系统如何按照年月日的方式来组织时间,组织时间的方式和地区,时区有很大关系.
NSDate?Components 只是一个容器，容器中详细包含了年月日时分等信息.
其中NSDate相信大家用的比较多,就不在这里赘述了,各位看官自行百度,今天主要和大家分享一下NSCalendar和NSDate?Components,下面举几个例子,并贴出代码,让大家能更好的理解.
1.拆分一个时间
NSDate * date = [NSDate date];//当前时间
NSCalendar * calendar = [NSCalendar currentCalendar];//当前用户的calendar
NSDateComponents * components = [calendar components:NSCalendarUnitMinute | NSCalendarUnitMonth | NSCalendarUnitHour | NSCalendarUnitDay fromDate:date];
NSLog(@"%ld月%ld日%ld时%ld分" ,(long)components.month,(long)components.day,(long)components.hour,(long)components.minute);
2.查看今天是在今年的第几周
NSCalendar * calendar = [NSCalendar currentCalendar];
NSDate * currentDate = [NSDate date];
NSInteger week = [calendar ordinalityOfUnit:NSCalendarUnitWeekday inUnit:NSCalendarUnitYear forDate:currentDate];
NSLog(@"今天是今年的第%ld周",week);
3.根据拆分时间返回NSDate
NSDateComponents * components = [[NSDateComponents alloc] init];
components.year = 2015;
components.month = 9;
components.day = 28;
components.hour = 14;
components.minute = 38;
components.second = 20;
NSCalendar * calendar = [NSCalendar currentCalendar];
NSDate * date = [calendar dateFromComponents:components];
NSDateFormatter * formatter = [[NSDateFormatter alloc] init];
formatter.dateFormat = @"yyyy年MM月dd日hh时mm分ss秒";
NSString * str = [formatter stringFromDate:date];
NSLog(@"%@",str);
4.相对时间(现在往后11天10小时)
NSDateComponents * components = [[NSDateComponents alloc] init];
components.day = 11;
components.hour = 10;
NSCalendar * calendar = [NSCalendar currentCalendar];
NSDate * currentDate = [NSDate date];
NSDate * nextData = [calendar dateByAddingComponents:components toDate:currentDate options:NSCalendarMatchStrictly];
NSDateFormatter * formatter = [[NSDateFormatter alloc] init];
formatter.dateFormat = @"yyyy年MM月dd日hh时mm分ss秒";
NSString * str = [formatter stringFromDate:nextData];
NSLog(@"%@",str);
5.这个月还有多少天
NSCalendar * calendar = [NSCalendar currentCalendar];
NSDate * currentDate = [NSDate date];
NSRange range = [calendar rangeOfUnit:NSCalendarUnitDay inUnit:NSCalendarUnitMonth forDate:currentDate];
6.补充
①.创建不同地区的NSCalendar
initWithCalendarIdentifier:
其中有效的identifer:
NSString * const NSGregorianCalendar;
NSString * const NSBuddhistCalendar;
NSString * const NSChineseCalendar;
NSString * const NSHebrewCalendar;
NSString * const NSIslamicCalendar;
NSString * const NSIslamicCivilCalendar;
NSString * const NSJapaneseCalendar;
NSString * const NSRepublicOfChinaCalendar;
NSString * const NSPersianCalendar;
NSString * const NSIndianCalendar;
NSString * const NSISO8601Calendar;
②.一周的开始日期
firstWeekday
③.地区和时区
locale 和 timeZone
④.所有的NSCalendarUnit
NSEraCalendarUnit = kCFCalendarUnitEra,
NSYearCalendarUnit = kCFCalendarUnitYear,
NSMonthCalendarUnit = kCFCalendarUnitMonth,
NSDayCalendarUnit = kCFCalendarUnitDay,
NSHourCalendarUnit = kCFCalendarUnitHour,
NSMinuteCalendarUnit = kCFCalendarUnitMinute,
NSSecondCalendarUnit = kCFCalendarUnitSecond,
NSWeekCalendarUnit = kCFCalendarUnitWeek,
NSWeekdayCalendarUnit = kCFCalendarUnitWeekday,
NSWeekdayOrdinalCalendarUnit = kCFCalendarUnitWeekdayOrdinal,
NSQuarterCalendarUnit = kCFCalendarUnitQuarter,
NSWeekOfMonthCalendarUnit = kCFCalendarUnitWeekOfMonth,
NSWeekOfYearCalendarUnit = kCFCalendarUnitWeekOfYear,
NSYearForWeekOfYearCalendarUnit = kCFCalendarUnitYearForWeekOfYear
NSCalendarCalendarUnit = (1 << 20),
NSTimeZoneCalendarUnit = (1 << 21).