计划的本地通知未存储在 ScheduledLocalNotification 数组中

Question

目前，如果用户当天尚未打开该应用程序，我目前安排本地通知在每天下午 6 点显示一次。如果用户已经加载了应用程序，那么我想取消当天的通知并安排明天下午 6 点的新通知。通知显示正常，但是，当我尝试迭代计划通知列表（这不是我在应用程序中拥有的唯一本地通知）时，[[UIApplication sharedApplication] ScheduledLocalNotifications] 数组始终为空。下面是给我带来麻烦的代码片段：

// See if we need to create a local notification to tell the user that they can receive a daily reward
NSArray *notifications = [[UIApplication sharedApplication] scheduledLocalNotifications]; // <- This is always empty
// Iterate over all the pending notifications
for( int iter = 0; iter < [notifications count]; iter++ )
{
    UILocalNotification* localNotification = [notifications objectAtIndex:iter];

    if( [[localNotification.userInfo objectForKey:@"source"] isEqualToString:@"dailyReminder"] )
        [[UIApplication sharedApplication] cancelLocalNotification:localNotification];
}

NSCalendar* calendar = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];
[calendar setTimeZone:[NSTimeZone localTimeZone]];
NSDateComponents *nowComponents = [calendar components:NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit | NSSecondCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit fromDate:serverDate];

int hour = [nowComponents hour];
int minute = [nowComponents minute];
int second = [nowComponents second];

int hoursToAdd = 18 - hour;

NSDateComponents *comps = [[[NSDateComponents alloc] init] autorelease];
[comps setDay:1];
[comps setHour:hoursToAdd];
[comps setMinute:-minute];
[comps setSecond:-second];
NSDate *tomorrow6PM = [calendar dateByAddingComponents:comps 
                                                toDate:serverDate
                                               options:0];

NSMutableDictionary* userInfo = [NSMutableDictionary dictionary];
[userInfo setObject:@"dailyReminder" forKey:@"source"];

scheduleNotification(tomorrow6PM, NSLocalizedString(@"Come Back!", @"daily reminder notification message"), NSLocalizedString(@"Launch", @"daily reminder notification button text"), [UIApplication sharedApplication].applicationIconBadgeNumber+1, userInfo);

scheduleNotification 函数很简单，只是构造一个本地通知：

void scheduleNotification(NSDate* fireIn, NSString* bodyText, NSString* alertText, NSUInteger badgeCount, NSMutableDictionary* userInfo)
{
static int appCount = 0;
appCount += 1;

if(!isLocalNotificationEnabled()) 
    return;

Class localNotificationClass = NSClassFromString(@"UILocalNotification");
UILocalNotification* localNotification = [[localNotificationClass alloc] init];
if(!localNotification)
    return;

localNotification.fireDate = fireIn;
localNotification.timeZone = [NSTimeZone systemTimeZone];
localNotification.alertBody = bodyText;
localNotification.alertAction = alertText;
localNotification.soundName = UILocalNotificationDefaultSoundName;
localNotification.applicationIconBadgeNumber = badgeCount;
localNotification.userInfo = userInfo;

[[UIApplication sharedApplication] scheduleLocalNotification:localNotification];
[localNotification release];
}

我不明白为什么本地通知数组始终为空。正如我之前所说，通知会在正确的时间显示，因此它们正在安排中。任何帮助表示赞赏。

Answer 1

现在也有类似的问题。我的猜测是，iOS 不会立即安排通知，而是仅在当前运行循环结束时安排通知。在同一运行循环中多次设置 ScheduledLocalNotifications 属性时，我遇到了这些问题，并且更改似乎没有相应更新。我想我会自己保留本地通知数组的副本，并且只设置 ScheduledLocalNotifications 并且从不读取它。

Answer 2

localNotification.fireDate = fireIn;

在这一行中检查 "fireIn" 是否是 NSDate 或 NSString 的对象。

如果是 NSString，则借助 NSDateformatter 将其转换为 NSDate 对象，然后将其赋值给 localNotification fireDate。

我之前遇到过同样的问题，并通过上述步骤解决了它。

Answer 3

如果计划有无效的触发日期，它将不会得到计划并返回结果空数组，因为从来没有有效的一个计划，尝试打印出您的 localNotification，如下所示，您可能会发现问题。

NSLog(@"Notification--->: %@", localNotification);