Objective-C语法之NSCalendar的使用（包含NSDateComponents）

  1 #import <Foundation/Foundation.h>
  2 /**
  3  *  根据输入的时间，获取对应月份的天数
  4  *
  5  *  @param currentDate 输入的时间
  6  *
  7  *  @return 对应月份的天数
  8  */
  9 NSUInteger daysOfMonth(NSDate *currentDate) {
 10     NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
 11     NSRange range = [gregorian rangeOfUnit:NSCalendarUnitDay inUnit:NSCalendarUnitMonth forDate:currentDate];
 12     return range.length;
 13 }
 14 /**
 15  *  根据输入的时间，获取对应年份的天数
 16  *
 17  *  @param currentDate 输入的时间
 18  *
 19  *  @return 对应年份的天数
 20  */
 21 NSUInteger daysOfYear(NSDate *currentDate) {
 22     NSUInteger days = 0;
 23     NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
 24     NSDateComponents *comps = [gregorian components:NSCalendarUnitYear fromDate:currentDate];
 25     
 26     for (NSUInteger i=1; i<=12; i++) {
 27         [comps setMonth:i];
 28         days += daysOfMonth([gregorian dateFromComponents:comps]);
 29     }
 30     return days;
 31 }
 32 /**
 33  *  根据输入的时间，获取对应月份的第一天时间
 34  *
 35  *  @param currentDate 输入的时间
 36  *
 37  *  @return 对应月份的第一天时间
 38  */
 39 NSDate* firstDayOfMonth(NSDate *currentDate) {
 40     NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
 41     unsigned unitFlags = NSCalendarUnitYear | NSCalendarUnitMonth |  NSCalendarUnitDay | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond;
 42     NSDateComponents *comps = [gregorian components:unitFlags fromDate:currentDate];
 43     [comps setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]]; //使用UTC或GMT解决时区相差8小时的问题
 44     [comps setDay:1];
 45     
 46     NSDate *firstDay = [gregorian dateFromComponents:comps];
 47     return firstDay;
 48 }
 49 /**
 50  *  根据输入的时间，获取对应月份的最后一天时间
 51  *
 52  *  @param currentDate 输入的时间
 53  *
 54  *  @return 对应月份的最后一天时间
 55  */
 56 NSDate* lastDayOfMonth(NSDate *currentDate) {
 57     NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
 58     unsigned unitFlags = NSCalendarUnitYear | NSCalendarUnitMonth |  NSCalendarUnitDay | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond;
 59     NSDateComponents *comps = [gregorian components:unitFlags fromDate:currentDate];
 60     [comps setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]]; //使用UTC或GMT解决时区相差8小时的问题
 61     [comps setDay:daysOfMonth(currentDate)];
 62     
 63     NSDate *lastDay = [gregorian dateFromComponents:comps];
 64     return lastDay;
 65 }
 66 /**
 67  *  根据输入的时间和添加的月数间隔、天数间隔，获取间隔后的时间
 68  *
 69  *  @param currentDate 输入的时间
 70  *  @param months      月数间隔
 71  *  @param days        天数间隔
 72  *
 73  *  @return 间隔后的时间
 74  */
 75 NSDate* addMonthAndDayToDate(NSDate *currentDate, NSUInteger months, NSUInteger days) {
 76     NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
 77     NSDateComponents *comps = [[NSDateComponents alloc] init];
 78     [comps setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]]; //使用UTC或GMT解决时区相差8小时的问题
 79     [comps setMonth:months];
 80     [comps setDay:days];
 81     
 82     NSDate *newDate = [gregorian dateByAddingComponents:comps toDate:currentDate options:0];
 83     return newDate;
 84 }
 85 /**
 86  *  根据输入的开始时间和结束时间，获取间隔的时间数组（月数和天数；toDate-fromDate的比较值是有符号整数NSInteger，所以存在负数的可能）
 87  *
 88  *  @param fromDate 开始时间
 89  *  @param toDate   结束时间
 90  *
 91  *  @return 间隔的时间数组（月数和天数；toDate-fromDate的比较值是有符号整数NSInteger，所以存在负数的可能）
 92  */
 93 NSArray* monthAndDayBetweenTwoDates(NSDate *fromDate, NSDate *toDate) {
 94     NSMutableArray *mArrMonthAndDay = [[NSMutableArray alloc] initWithCapacity:2];
 95     NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
 96     unsigned unitFlags = NSCalendarUnitMonth |  NSCalendarUnitDay;
 97     NSDateComponents *comps = [gregorian components:unitFlags fromDate:fromDate toDate:toDate options:0];
 98     
 99     [mArrMonthAndDay addObject:[NSString stringWithFormat:@"%ld", (long)[comps month]]];
100     [mArrMonthAndDay addObject:[NSString stringWithFormat:@"%ld", (long)[comps day]]];
101     return mArrMonthAndDay;
102 }
103 int main(int argc, const char * argv[]) {
104     @autoreleasepool {
105         NSDate *now = [NSDate date];
106         NSUInteger days = daysOfMonth(now);
107         NSLog(@"本月的天数=%lu", (unsigned long)days); //本月的天数=30
108         
109         days = daysOfYear(now);
110         NSLog(@"本年的天数=%lu", (unsigned long)days); //本年的天数=365
111         
112         NSDate *firstDay = firstDayOfMonth(now);
113         NSLog(@"firstDayOfMonth=%@", firstDay); //firstDayOfMonth=2015-04-01 00:58:39 +0000
114         
115         NSDate *lastDay = lastDayOfMonth(now);
116         NSLog(@"lastDayOfMonth=%@", lastDay); //lastDayOfMonth=2015-04-30 00:58:39 +0000
117         
118         NSDate *newDate = addMonthAndDayToDate(lastDay, 0, 2);
119         NSLog(@"lastDayOfMonth的后天=%@", newDate); //lastDayOfMonth的后天=2015-05-02 00:58:39 +0000
120         
121         newDate = addMonthAndDayToDate(lastDay, 2, 2);
122         NSLog(@"lastDayOfMonth的2个月零2天后时间=%@", newDate); //lastDayOfMonth的2个月零2天后时间=2015-07-02 00:58:39 +0000
123         
124         NSArray *arrMonthAndDay = monthAndDayBetweenTwoDates(firstDay, newDate);
125         NSLog(@"lastDayOfMonth的2个月零2天后时间和firstDayOfMonth相差（%@个月零%@天）", arrMonthAndDay[0], arrMonthAndDay[1]); //lastDayOfMonth的2个月零2天后时间和firstDayOfMonth相差（3个月零1天）
126     }
127     return 0;
128 }

1 2015-04-30 00:58:39.794 OCNSCalendar[988:83921] 本月的天数=30
2 2015-04-30 00:58:39.795 OCNSCalendar[988:83921] 本年的天数=365
3 2015-04-30 00:58:39.800 OCNSCalendar[988:83921] firstDayOfMonth=2015-04-01 00:58:39 +0000
4 2015-04-30 00:58:39.800 OCNSCalendar[988:83921] lastDayOfMonth=2015-04-30 00:58:39 +0000
5 2015-04-30 00:58:39.800 OCNSCalendar[988:83921] lastDayOfMonth的后天=2015-05-02 00:58:39 +0000
6 2015-04-30 00:58:39.800 OCNSCalendar[988:83921] lastDayOfMonth的2个月零2天后时间=2015-07-02 00:58:39 +0000
7 2015-04-30 00:58:39.800 OCNSCalendar[988:83921] lastDayOfMonth的2个月零2天后时间和firstDayOfMonth相差（3个月零1天）