0

我想创建一个简单的药丸提醒 iOS 应用程序(让我们暂时将通知放在一边)。我想为具有重复的药丸创建单个数据库记录,并检查特定日期是否与重复“生成”的日期相交。

示例:我设置了从 4 月 12 日开始到 4 月 20 日结束的药片期,每 2 天重复一次,下午 3 点。所以这个药片在这个日期有效:

  • 4 月 12 日下午 3 点
  • 4 月 14 日下午 3 点
  • 4 月 16 日下午 3 点
  • 4 月 18 日下午 3 点
  • 4 月 20 日下午 3 点

问题:

  • 哪种数据可以描述“每 2 天”的信息?NSDateInterval 会是一个很好的解决方案吗?

  • 如何验证特定日期是否符合我的重复计划?(即检查 4 月 13 日是否是上一个示例的有效日期并得到“否”作为答案)

4

1 回答 1

2

这是一个应该满足您的条件的示例类:

主文件

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

int main(int argc, const char * argv[])
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

    // Specify a period in days
    NSInteger period = 2;

    // Set the start/end/current days.  These can be retrieved from a database or elsewhere
    NSDate *startDate = [NSDate dateWithString:@"2012-04-12 00:00:00 +0000"];
    NSDate *endDate = [NSDate dateWithString:@"2012-04-20 00:00:00 +0000"];
    NSDate *currentDate = [NSDate dateWithString:@"2012-04-14 00:00:00 +0000"];

    // Actually do the checking.  This could alternatively be offloaded to a function in DateChecker
    if([DateChecker date:currentDate isBetweenDate:startDate andDate:endDate])
    {
        if([DateChecker date:currentDate fallsOnStartDate:startDate withInterval:period])
        {
            NSLog(@"The date %@ falls in the specified date period & is on the interval date.", currentDate);
        }
        else
        {
            NSLog(@"The date %@ falls in the specified date period & is NOT on the interval date.", currentDate);
        }
    }
    else
    {
        NSLog(@"The date %@ does not fall in the specified date period.", currentDate);
    }

    [pool release];

    return 0;
}

日期检查器.h

#import <Foundation/Foundation.h>

@interface DateChecker : NSObject
{
}
+ (BOOL)date:(NSDate*)date fallsOnStartDate:(NSDate*)beginDate withInterval:(NSInteger)daysInterval;
+ (BOOL)date:(NSDate*)date isBetweenDate:(NSDate*)beginDate andDate:(NSDate*)endDate;

@end

日期检查器.m

#import "DateChecker.h"

@implementation DateChecker

+ (BOOL)date:(NSDate*)date fallsOnStartDate:(NSDate*)beginDate withInterval:(NSInteger)daysInterval
{
    NSDateComponents *components;
    NSInteger days;

    // Get the number of days since the start date
    components = [[NSCalendar currentCalendar] components: NSDayCalendarUnit fromDate: beginDate toDate: date options: 0];
    days = [components day];

    // If the number of days passed falls on the interval, then retrun YES
    if(days % daysInterval == 0)
    {
        return YES;
    }
    else
    {
        return NO;
    }
}

+ (BOOL)date:(NSDate*)date isBetweenDate:(NSDate*)beginDate andDate:(NSDate*)endDate
{
    if ([date compare:beginDate] == NSOrderedAscending)
        return NO;

    if ([date compare:endDate] == NSOrderedDescending) 
        return NO;

    return YES;
}

@end

这应该让您了解如何编写一个可以处理您的要求的类。我将它作为命令行应用程序运行,它似乎工作正常。功能

+ (BOOL)date:(NSDate*)date isBetweenDate:(NSDate*)beginDate andDate:(NSDate*)endDate

是从如何检查 NSDate 是否发生在其他两个 NSDate 之间慷慨地获得的。

于 2012-05-21T08:15:15.617 回答