从 EventStore EventKit iOS 获取所有事件

Question

我想知道如何在 iOS 中使用 EventKit 从 EventStore 获取所有事件。

这样我就可以指定今天的所有事件：

- (NSArray *)fetchEventsForToday {

    NSDate *startDate = [NSDate date];

    // endDate is 1 day = 60*60*24 seconds = 86400 seconds from startDate
    NSDate *endDate = [NSDate dateWithTimeIntervalSinceNow:86400];

    // Create the predicate. Pass it the default calendar.
    NSArray *calendarArray = [NSArray arrayWithObject:defaultCalendar];
    NSPredicate *predicate = [self.eventStore predicateForEventsWithStartDate:startDate endDate:endDate calendars:calendarArray]; 

    // Fetch all events that match the predicate.
    NSArray *events = [self.eventStore eventsMatchingPredicate:predicate];

    return events;
}

正确的应该使用 NSPredicate，它的创建方式是：

NSPredicate *predicate = [self.eventStore predicateForEventsWithStartDate:startDate endDate:endDate calendars:calendarArray]; 

我尝试使用

distantPast
distantFuture

as startDate 和 endDate，但没有效果。 所以其他 Q 中的其他 A 并不是我正在寻找的。

谢谢你！

---

编辑

我已经测试并得出结论，我只能获取最多 4 年时间内的事件。有办法克服这个吗？不使用多次获取..

Answer 1

将所有事件提取到数组中的代码：

NSDate *start = ...
NSDate *finish = ...

// use Dictionary for remove duplicates produced by events covered more one year segment
NSMutableDictionary *eventsDict = [NSMutableDictionary dictionaryWithCapacity:1024];

NSDate* currentStart = [NSDate dateWithTimeInterval:0 sinceDate:start];

int seconds_in_year = 60*60*24*365;

// enumerate events by one year segment because iOS do not support predicate longer than 4 year !
while ([currentStart compare:finish] == NSOrderedAscending) {

    NSDate* currentFinish = [NSDate dateWithTimeInterval:seconds_in_year sinceDate:currentStart];

    if ([currentFinish compare:finish] == NSOrderedDescending) {
        currentFinish = [NSDate dateWithTimeInterval:0 sinceDate:finish];
    }
    NSPredicate *predicate = [eventStore predicateForEventsWithStartDate:currentStart endDate:currentFinish calendars:nil];
    [eventStore enumerateEventsMatchingPredicate:predicate
                                      usingBlock:^(EKEvent *event, BOOL *stop) {

                                          if (event) {
                                              [eventsDict setObject:event forKey:event.eventIdentifier];
                                          }

                                      }];       
    currentStart = [NSDate dateWithTimeInterval:(seconds_in_year + 1) sinceDate:currentStart];

}

NSArray *events = [eventsDict allValues];

Answer 2

这是我在应用程序中使用的方法来获取它们。

    NSDate *startDate = [NSDate distantPast];       
    NSDate *endDate = [NSDate distantFuture];

Answer 3

这是生产中的代码

const double secondsInAYear = (60.0*60.0*24.0)*365.0;
NSPredicate* predicate = [eventStore predicateForEventsWithStartDate:[NSDate dateWithTimeIntervalSinceNow:-secondsInAYear] endDate:[NSDate dateWithTimeIntervalSinceNow:secondsInAYear] calendars:nil];

对于您来说，我建议您回顾和展望十年。