ios - 当 iBeacon 范围为 "Immediate"或 "near"时如何通知用户？

Question

用户只有在离信标足够近时才会收到通知，因为那时 didEnterRegion 无法正常工作。
我的代码是这样的:

if ([region isKindOfClass:[CLBeaconRegion class]] && ([beaconRegionInStringFormat isEqualToString:@"Immediate"] || [beaconRegionInStringFormat isEqualToString:@"Near"]))
{
    UILocalNotification *notification = [[UILocalNotification alloc] init];
    notification.alertBody = @"Please open the application";
    [[UIApplication sharedApplication] presentLocalNotificationNow:notification];
}

但通知将继续发送给用户。我怎样才能只收到一次通知？

Answer 1

1. 给你的 Controller 添加一个标志

界面:
@property (nonatomic) BOOL userNotified;
执行:

if (!self.userNotified && [region isKindOfClass:[CLBeaconRegion class]] && ([beaconRegionInStringFormat isEqualToString:@"Immediate"] || [beaconRegionInStringFormat isEqualToString:@"Near"]))
{
    UILocalNotification *notification = [[UILocalNotification alloc] init];
    notification.alertBody = @"Please open the application";
    [[UIApplication sharedApplication] presentLocalNotificationNow:notification];
    self.userNotified = YES;
}

2. 使用 GCD (Grand Central Dispatch)

使用此方法，每次应用启动时代码只会执行一次。

static dispatch_once_t onceToken;
dispatch_once (&onceToken, ^{
    if ([region isKindOfClass:[CLBeaconRegion class]] && ([beaconRegionInStringFormat isEqualToString:@"Immediate"] || [beaconRegionInStringFormat isEqualToString:@"Near"]))
    {
        UILocalNotification *notification = [[UILocalNotification alloc] init];
        notification.alertBody = @"Please open the application";
        [[UIApplication sharedApplication] presentLocalNotificationNow:notification];
    }
});