ios - NSDate 过滤案例

Question

我正在使用 transient 属性在 TableView 部分中分发核心数据对象。 transient 属性 称为sectionIdentifier，它是根据名为todoDueDate 的属性定义的。我需要以必须包含以下组之一的方式过滤对象，并且只包含一个:

1. sectionIdentier = 0, **OVERDUE** , todoDueDate < today
2. sectionIdentier = 1, **TODAY** , todoDueDate = today
3. sectionIdentier = 2, **TOMORROW** , todoDueDate >today AND todoDueDate= = tomorrow
4. sectionIdentier = 3, **UPCOMING** , todoDueDate > today AND todoDueDate!=tomorrow

使用我当前的代码，我可以过滤案例 1、2 和 4 的对象(我必须在明天丢弃这里的对象)。我已经尝试了几种方法来过滤案例 3 的对象，但没有成功。我恳请你帮我过滤案例 3。这是我当前的代码:

-(NSString *)sectionIdentifier{

    [self willAccessValueForKey:@"sectionIdentifier"];
    NSString *tmp = [self primitiveValueForKey:@"sectionIdentifier"];
    [self didAccessValueForKey:@"sectionIdentifier"];

    if (!tmp){

        NSDate *date = self.todoDueDate;
        NSDate *todayDate = [NSDate date];


        NSLog(@"date= %@",date);
        NSLog(@"todayDate = %@",todayDate);


        NSCalendar *calendar = [NSCalendar currentCalendar];
        NSInteger comps = (NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit);
        NSDateComponents *date1Components = [calendar components:comps fromDate:date];
        NSDateComponents *date2Components = [calendar components:comps fromDate:todayDate];

        date = [calendar dateFromComponents:date1Components];
        todayDate = [calendar dateFromComponents:date2Components];


        if([date
            compare:todayDate] == NSOrderedAscending) {
            tmp = @"0";//OVERDUE
        }
        if([date
          compare:todayDate] == NSOrderedDescending)  {
          tmp = @"3";//UPCOMING BUT NOT TOMORROW(PENDING THIS PART)
        }
        if ([date
             compare:todayDate] == NSOrderedSame) {
            tmp = @"1";//TODAY
        }


   //TOMORROW COMES HERE



        NSLog(@"Tmp= %@",tmp);

        [self setPrimitiveValue:tmp forKey:@"sectionIdentifier"];

    }
    return tmp;

}

---

这是我更新后的代码:

-(NSString *)sectionIdentifier{

    [self willAccessValueForKey:@"sectionIdentifier"];
    NSString *tmp = [self primitiveValueForKey:@"sectionIdentifier"];
    [self didAccessValueForKey:@"sectionIdentifier"];

    if (!tmp){
        NSDate *today = [NSDate date];
        NSDate *date = self.todoDueDate;
        NSCalendar *calendar;
        NSInteger daysAfterToday = [calendar components:NSDayCalendarUnit
                                               fromDate:today toDate:date options:0].day;
       // NSString *section;
        if (daysAfterToday < 0) {
            tmp  = @"0";
        } else if (daysAfterToday == 0) {
            tmp = @"1";
        } else if (daysAfterToday == 1) {
            tmp = @"2";
        } else {
            tmp = @"3";
        }


        NSLog(@"TODAY = %@", today);
        NSLog(@"DATE = %@", date);
        NSLog(@"DAYS AFTER TODAY = %ld",(long)daysAfterToday);

        NSLog(@"Tmp= %@",tmp);

        [self setPrimitiveValue:tmp forKey:@"sectionIdentifier"];

    }
    return tmp;

}

这里是日志记录结果:

2014-01-17 22:35:53.576 To-Do Pro Light[4124:a0b] TODAY = 2014-01-18 05:35:53 +0000
2014-01-17 22:35:53.619 To-Do Pro Light[4124:a0b] DATE = 2014-01-13 04:08:32 +0000
2014-01-17 22:35:53.656 To-Do Pro Light[4124:a0b] DAYS AFTER TODAY = 0
2014-01-17 22:35:53.664 To-Do Pro Light[4124:a0b] Tmp= 1
2014-01-17 22:35:53.739 To-Do Pro Light[4124:a0b] TODAY = 2014-01-18 05:35:53 +0000
2014-01-17 22:35:53.743 To-Do Pro Light[4124:a0b] DATE = 2014-01-18 04:13:39 +0000
2014-01-17 22:35:53.748 To-Do Pro Light[4124:a0b] DAYS AFTER TODAY = 0
2014-01-17 22:35:53.752 To-Do Pro Light[4124:a0b] Tmp= 1
2014-01-17 22:35:53.757 To-Do Pro Light[4124:a0b] TODAY = 2014-01-18 05:35:53 +0000
2014-01-17 22:35:53.762 To-Do Pro Light[4124:a0b] DATE = 2014-01-19 04:16:14 +0000
2014-01-17 22:35:53.766 To-Do Pro Light[4124:a0b] DAYS AFTER TODAY = 0
2014-01-17 22:35:53.770 To-Do Pro Light[4124:a0b] Tmp= 1
2014-01-17 22:35:53.776 To-Do Pro Light[4124:a0b] TODAY = 2014-01-18 05:35:53 +0000
2014-01-17 22:35:53.779 To-Do Pro Light[4124:a0b] DATE = 2014-01-25 04:11:34 +0000
2014-01-17 22:35:53.825 To-Do Pro Light[4124:a0b] DAYS AFTER TODAY = 0
2014-01-17 22:35:53.831 To-Do Pro Light[4124:a0b] Tmp= 1

Answer 1

只需让日历计算从今天到截止日期的天数，并检查该数字:

        NSInteger daysAfterToday = [calendar components:NSDayCalendarUnit
            fromDate:today toDate:date options:0].day;
        NSString *section;
        if (daysAfterToday < 0) {
            section = @"0";
        } else if (daysAfterToday == 0) {
            section = @"1";
        } else if (daysAfterToday == 1) {
            section = @"2";
        } else {
            section = @"3";
        }