将 UILocalNotification 与核心位置一起使用

Question

我有这段代码，每次本地 JSON 文件中发生的事件与他当前位置之间的距离小于 100 米时，我都会发送用户通知，询问他是否在该事件中，当他按下是时该活动将被标记为已参加。问题是我试图通过使用我在网上找到的一些代码来做到这一点，但我不确定这是否是正确的方法，无论如何我在我的 iPhone 上测试了它，当我到达一个活动地点时发生了什么不断发送不可阻挡的通知，当我尝试按是或否时，实际上什么也没发生，它会继续发送这些通知。谁能帮我解释一下出了什么问题，我对 Xcode 和 Objective-C 语言不是很熟悉。我使用的代码如下所示。

在 AppDelegate.m 中

     - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
           {
             // load Core Data
              NSManagedObjectContext *context = [self managedObjectContext];
              if (!context) {
                  NSLog(@"No NSManagedObjectContext generated");
               }
               NSLog(@"DelegateApp Managed Object Context = %@", context);
              [[DataManager sharedInstance] setManagedObjectContext:context];
              [[DataManager sharedInstance] initDataBase];
              return YES;

          UILocalNotification *notification = [launchOptions   objectForKey:UIApplicationLaunchOptionsLocalNotificationKey];

       if (notification) {
           [self showAlarm:notification.alertBody];
           NSLog(@"AppDelegate didFinishLaunchingWithOptions");
           application.applicationIconBadgeNumber = 0;
       }

      [self.window makeKeyAndVisible];
       return YES;
    }

     - (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification {
         [self showAlarm:notification.alertBody];
         application.applicationIconBadgeNumber = 0;
         NSLog(@"AppDelegate didReceiveLocalNotification %@", notification.userInfo);
      }


    - (void)showAlarm:(NSString *)text {
             UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"SPOT IT"
                                                    message:text delegate:self
                                          cancelButtonTitle:@"YES"
                                          otherButtonTitles:@"NO",nil];

             [alertView show];
     }


    - (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
       {
           NSString *title = [alertView buttonTitleAtIndex:buttonIndex];

           if([title isEqualToString:@"NO"])
           {
             NSLog(@"Button 2 was selected.");
           }
           else if([title isEqualToString:@"YES"])
           {
            NSLog(@"Button 1 was selected.");

            // attended
           [_eachEvent setHasATTENDED:[NSNumber numberWithBool:TRUE]];
         // save
          NSError *error = nil;
          if (![_managedObjectContext save:&error])
          {
           NSLog(@"Error in saving");
          }

      }
  }

在我的 DataManager 类中：

  - (void) locationManager:(CLLocationManager *)manager
 didUpdateToLocation:(CLLocation *)newLocation
        fromLocation:(CLLocation *)oldLocation {

//NSLog(@"MV_EventsDataManager new location: latitude %+.6f, longitude %+.6f\n", newLocation.coordinate.latitude,  newLocation.coordinate.longitude);
for (Event *musicevent in [self loadTodaysEvents]) {

    // distance
    CLLocationDegrees lat = [musicevent.lat doubleValue];
    CLLocationDegrees lon = [musicevent.longi doubleValue];
    CLLocation *evLocation = [[CLLocation alloc] initWithLatitude:lat longitude:lon];
    double distance = [evLocation distanceFromLocation:newLocation];
    //NSLog(@"\t Calculated KM %@ to %@", [NSString stringWithFormat:@"%.1f",(distance/1000.0)], musicevent.title);

    // CLOSE !
    if (distance <= 100) {

        [[UIApplication sharedApplication] cancelAllLocalNotifications];

        UILocalNotification *localNotification = [[UILocalNotification alloc] init];

        localNotification.alertBody = @"Are u there!";
        localNotification.soundName = UILocalNotificationDefaultSoundName;
        localNotification.applicationIconBadgeNumber = 1; // increment

        //  NSDictionary *infoDict = [NSDictionary dictionaryWithObjectsAndKeys:@"Object 1", @"Key 1", @"Object 2", @"Key 2", nil];
        // localNotification.userInfo = infoDict;

        [[UIApplication sharedApplication] scheduleLocalNotification:localNotification];
     }

   }

}

Answer 1

根据您设置位置管理器的方式，委托方法 locationManager:didUpdateToLocation:fromLocation: 通常会每秒调用一次并进行位置更新。因此，您的代码一遍又一遍地发布本地通知。您需要跟踪发布通知的时间，以避免重复发布。