Fetch all events from EventStore EventKit iOS

问题:

i would like to know how to fetch all events from an EventStore using EventKit in iOS.

This way i can specify all events for today:

- (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;
}

The correct should use a NSPredicate, which is created with:

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

I have tried using

distantPast
distantFuture

as startDate and endDate, no good. So other A's from other Q's are not exaclty wha im looking for.

Thank you!

---

EDIT

I have tested and got to the conclusion that i can only fetch events in a period of 4 years maximum. Any way of getting past this? Without using multiple fetches..

回答1:

Code for fetch all events into array :

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];

回答2:

This is the method I am using in my app to fetch them.

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

回答3:

This is code in production

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

For you, I would recommend looking back and forward ten years.