calendarsForEntityType：EKEntityTypeReminder第一次为空，随后工作

Question

有人可以帮我弄清楚我在做什么错。我的应用程序应该访问iPhone的各种日历以检查即将发生的事件。因此，我需要访问日历中的“事件”以及“提醒”。当我有事件时，我将它们临时存储在UserDefaults中。

在我的.h文件中，我有类似的东西

@property (nonatomic, strong) EKEventStore *eventStore;
@property (nonatomic, strong) NSMutableArray *calendars;
@property (nonatomic, strong) NSMutableArray *reminders;
@property (nonatomic) BOOL accessToCalendarsGranted;
@property (nonatomic) BOOL accessToRemindersGranted;
而且我需要获得用户的许可才能访问它们，因此在主代码中，我有这样的代码：

    -(void)requestCalendarAccess
{
    // Prompt the user for access to their Calendar

    [_eventStore requestAccessToEntityType:EKEntityTypeEvent completion:^(BOOL granted, NSError *error){
        if (!granted)
        {
            NSLog(@"user has not granted access to calendars!!");
            // Display a message if the user has denied or restricted access to Calendar
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:NSLocalizedString(@"Privacy Warning", nil)
                                                            message:NSLocalizedString(@"Permission was not granted for Calendar", nil)
                                                           delegate:nil
                                                  cancelButtonTitle:NSLocalizedString(@"Dismiss", nil)
                                                  otherButtonTitles:nil];
            [alert show];

            return;
        }

        // Let's ensure that our code will be executed from the main queue
        dispatch_async(dispatch_get_main_queue(), ^{
            // The user has granted access to their Calendar
            [self accessGrantedForCalendar];
        });
    }];
}
由accessGrantedForCalendar中的代码完成

_calendars = [[NSUserDefaults standardUserDefaults] objectForKey:kCalendarListKey];

//if we have calendars stored in user defaults, we go and read them
if(!_calendars)
{
    _calendars = [[NSMutableArray alloc] init];
    NSArray *phoneCalendarArray = [_eventStore calendarsForEntityType:EKEntityTypeEvent];

for (EKCalendar *systemCalendar in phoneCalendarArray)
{
    NSMutableDictionary *calendarDict = [NSMutableDictionary dictionaryWithObjectsAndKeys:[systemCalendar title], kCalendarName, [systemCalendar calendarIdentifier], kCalendarIndentifier, [NSNumber numberWithBool:YES], kCalendarWatched,  nil];

    [_calendars addObject:calendarDict];
}

[[NSUserDefaults standardUserDefaults] setObject:_calendars forKey:kCalendarListKey];
[[NSUserDefaults standardUserDefaults] synchronize];

}
而且现在一切都很好。许多其他的实际获得事件的代码不在此处。当我尝试相同的提醒方法时，问题就来了：

-(void)requestRemindersAccess
{
    [self.eventStore requestAccessToEntityType:EKEntityTypeReminder completion:^(BOOL granted, NSError *error){
        if (granted)
        {
            // Let's ensure that our code will be executed from the main queue
            dispatch_async(dispatch_get_main_queue(), ^{
            // The user has granted access to their Calendar
                [self accessGrantedForReminder];
            });
        }
        else
        {
            NSLog(@"user has not granted access to reminders!!");
            // Display a message if the user has denied or restricted access to Calendar
            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:NSLocalizedString(@"Privacy Warning", nil)
                                                            message:NSLocalizedString(@"Permission was not granted for Reminders", nil)
                                                           delegate:nil
                                                  cancelButtonTitle:NSLocalizedString(@"Dismiss", nil)
                                                  otherButtonTitles:nil];
            [alert show];
        }
    }];
}
以及完成accessGrantedForReminder中的代码：

_reminders = [[NSUserDefaults standardUserDefaults] objectForKey:kRemindersListKey];

//if we don't have reminders stored in user defaults, we go and read them
if(!_reminders || _reminders.count == 0)
{
    _reminders = [[NSMutableArray alloc] init];
    //FOLLOWING LINE HAS PROBLEM FIRST TIME!!!
    NSArray *phoneReminderArray = [_eventStore calendarsForEntityType:EKEntityTypeReminder];

for (EKCalendar *systemCalendar in phoneReminderArray)
{
    NSMutableDictionary *calendarDict = [NSMutableDictionary dictionaryWithObjectsAndKeys:[systemCalendar title], kCalendarName, [systemCalendar calendarIdentifier], kCalendarIndentifier, [NSNumber numberWithBool:YES], kCalendarWatched,  nil];

    [_reminders addObject:calendarDict];
}

[[NSUserDefaults standardUserDefaults] setObject:_reminders forKey:kRemindersListKey];
[[NSUserDefaults standardUserDefaults] synchronize];

}
上面指出的行有问题-第一次运行应用程序（即在获得许可后立即运行），我发现phoneReminderArray中有零个对象。如果我退出程序并再次运行，phoneReminderArray将得到一个对象。这让我发疯了-为什么它仅在我退出应用程序后才起作用（而其他日历“家庭，工作和生日”日历都似乎马上出现了？

有任何想法吗？

FYI，我查看了此related question，它帮助我找出了第一批日历事件的最初问题，但对提醒没有帮助

有人可以帮我弄清楚我在做什么错。我的应用程序应该访问iPhone的各种日历以检查即将发生的事件。因此，我需要访问日历中的“事件”，还需要...

Answer 1

解决方案实际上非常简单。在您致电以下行以获取提醒之前：

Answer 2

在talashar回答后，我无法使它工作，我也尝试了类似的refreshSourcesIfNecessary方法，但无济于事。

Answer 3

Swift版本