Objective-C实现两个日期之间的天数差

最新推荐文章于 2022-02-16 17:43:15 发布

原创最新推荐文章于 2022-02-16 17:43:15 发布 · 1.6k 阅读

1 ·

CC 4.0 BY-SA版权

文章标签：

#objective-c #对象 #类 #NSCalendarDate #interface

OC 专栏收录该内容

30 篇文章

订阅专栏

本文介绍了如何使用Objective-C来计算两个日期之间的天数差，主要涉及NSCalendarDate和相关类的使用。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

ElapsedDays.h头文件

#import <Foundation/Foundation.h>

@interface NSCalendarDate (ElapsedDays)
-(unsigned long) numberOfElapsedDays: (NSCalendarDate *) theDate;
@end

ElapsedDays.m源文件

#import "ElapsedDays.h"

#define IS_LEAP_YEAR(y) (y % 4 == 0 && y % 100 != 0 || y % 400 == 0)

@implementation NSCalendarDate (ElapsedDays)

-(unsigned long) numberOfElapsedDays: (NSCalendarDate *) theDate
{
    int             years, months, days;
    unsigned long   totDays = 0;
    NSCalendarDate *minDate, *maxDate;
    int             maxDateYear, maxDateMonth, minDateYear, minDateMonth;
    int             dayPerMonth[12] = {31, 0, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    
    if (self < theDate) {
        minDate = self;
        maxDate = theDate;
    } else {
        minDate = theDate;
        maxDate = self;
    }
    [maxDate years:     &years 
             months:    &months
             days:      &days
             hours:     NULL
             minutes:   NULL
             seconds:   NULL
             sinceDate: minDate
    ];
    minDateYear  = [minDate yearOfCommonEra];
    maxDateYear  = [maxDate yearOfCommonEra];
    minDateMonth = [minDate monthOfYear];
    maxDateMonth = [maxDate monthOfYear];    
    int y = minDateYear;
    int m = minDateMonth;
    // loop as long as the maxDate is not reached
    while (!(y == maxDateYear && m == maxDateMonth)) 
    {
        if (m != 2)
        {
            totDays += dayPerMonth[m - 1];
        }
        else 
        {
            if IS_LEAP_YEAR(y)
            {
                totDays += 29;
            }
            else
            {
                totDays += 28;
            }
        }  
        // calculate the next date in term of year and month
        if (m == 12) 
        {
            y++;
            m = 1;
        } 
        else
        {
            m++;  
        }
    }
    totDays += days;
    return totDays;
}
@end

test.m源文件

#import <Foundation/Foundation.h>
#import "ElapsedDays.h"

int main (int argc, const char * argv[])
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    
    NSCalendarDate *thisDate = [[NSCalendarDate alloc] initWithYear: 1999
                                                          month:      10
                                                          day:        14
                                                          hour:       0
                                                          minute:     0
                                                          second:     0
                                                          timeZone:   nil
                                ];
    NSCalendarDate *thatDate = [[NSCalendarDate alloc] initWithYear: 2010
                                                          month:       10
                                                          day:         14
                                                          hour:        0
                                                          minute:      0
                                                          second:      0
                                                          timeZone:    nil
                                 ];
                                 
    unsigned long days = [thisDate numberOfElapsedDays: thatDate];
    
    NSLog(@"\nBetween the\n %@ \nand the\n %@ \nthere are %lu days.", thisDate , thatDate, days);
    [pool drain];
    return 0;
}