didReceiveRemoteNotification 调用了两次

Question

我已经在我的应用中实现了推送通知。

当我的应用程序在前台时，我的应用程序工作正常。

但当应用程序在后台或被杀死时，我的didReceiveRemoteNotification 会调用两次。

我做了一个处理推送通知的通用方法，并从didFinishLaunchingWithOptions和didReceiveRemoteNotification调用这个方法

这是我的实现：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

  NSDictionary *pushDictionary = [launchOptions valueForKey:UIApplicationLaunchOptionsRemoteNotificationKey];
  if (pushDictionary) {
    [self customPushHandler:pushDictionary];
  }

  return YES;

}

还有：

- (void)application:(UIApplication *)application
   didReceiveRemoteNotification:(NSDictionary *)userInfo
  fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))handler {


         [self customPushHandler:userInfo];

 }

与：

 - (void) customPushHandler:(NSDictionary *)notification {

     // Code to push ViewController

         NSLog(@"Push Notification"); //Got it two times when Clicked in notification banner

   }

当我的应用程序运行时，ViewController 被推送一次。当我从通知横幅打开我的应用程序时，我的屏幕会被推送两次。

我在customPushHandler 中放置了一个 NSLog，当应用程序处于前台时我得到了一次，当我从通知横幅启动它时得到了两次。

我的代码有什么问题？

Answer 1

"当应用程序在后台时，该方法会被调用两次，一次是在您收到推送通知时，另一次是在您点击该通知时。"

如果应用处于后台，您可以验证应用状态并忽略收到的通知。

解决方案：Remote notification method called twice

Swift 4 代码：

func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {

        if (application.applicationState == .background) {
            completionHandler(.noData)
            return
        }

    // logic
    // call completionHandler with appropriate UIBackgroundFetchResult
}

Answer 2

每当您使用 backgroundFetch 进行远程通知时，请为此添加一个完成处理程序。

- (void)application:(UIApplication *)application
   didReceiveRemoteNotification:(NSDictionary *)userInfo
   fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))handler {

    [self customPushHandler:userInfo];

    completionHandler(UIBackgroundFetchResultNewData)
}

Answer 3

在 didReceiveRemoteNotification 中检查这一条件，例如 如果您在应用处于后台时点击通知。这样，您可以避免被调用两次。

 - (void)application:(UIApplication *)application
didReceiveRemoteNotification:(NSDictionary *)userInfo
fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))handler {
      UIApplicationState state = [[UIApplication sharedApplication] applicationState];
      if (state == UIApplicationStateBackground || state == UIApplicationStateInactive || state == UIApplicationStateForeground || state == UIApplicationStateActive)
      {
          //Do checking here.
          [self customPushHandler:userInfo];
      }
}

检查我是否已编辑我的答案。

Answer 4

检查当前导航堆栈中的顶视图控制器，如：

if(![self.navigationController.topViewController isKindOfClass:[MyClass class]]) {

           //code for pushing new controller

 }