iOS 9下前台点击FCM推送无法跳转指定ViewController求助

Hey there! Let's tackle this issue you're facing with FCM push notifications on your iPhone 4s (iOS 9) — where tapping your custom banner in the foreground fails to jump to the specified ViewController. iOS 9 has some push handling quirks compared to newer versions, and combining that with a third-party custom banner can lead to missed click bindings or incorrect navigation logic. Here's your step-by-step fix:

1. Verify Your Custom Banner's Tap Event is Bound Correctly #

First things first: if your custom banner isn't triggering any action on tap, the navigation code won't run at all. Double-check how you're setting up the banner's tap callback:

• Make sure you're explicitly binding a tap handler that includes your navigation logic, not just displaying the banner. For example:

  // Example with a closure-based tap handler (adjust to match your banner library's API)
  let customBanner = YourThirdPartyBanner()
  customBanner.title = "Your Push Title"
  customBanner.subtitle = "Your Push Body"
  
  // Bind the tap action
  customBanner.onTap = { [weak self] in
      guard let self = self else { return }
      // Navigate to your target VC here
      let targetVC = YourTargetViewController()
      
      // Adjust based on your root controller type
      if let navController = self.window?.rootViewController as? UINavigationController {
          navController.pushViewController(targetVC, animated: true)
      } else {
          self.window?.rootViewController?.present(targetVC, animated: true)
      }
  }
  
  customBanner.show()
  

• Use weak self to avoid memory leaks, and confirm you're accessing the correct root view controller (nav, tab bar, etc.) for your app's structure.

2. Fix Your didReceiveRemoteNotification Logic (iOS 9-Specific) #

In iOS 9, the system doesn't show a native notification banner when your app is in the foreground — you have to handle that manually. Make sure you're parsing the push payload and passing navigation data to your banner:

func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any]) {
    // Parse navigation parameters from the push payload (adjust keys to match your FCM setup)
    let targetIdentifier = userInfo["target_vc"] as? String ?? ""
    
    // Show your custom banner with the parsed data
    self.displayCustomPushBanner(userInfo: userInfo, targetID: targetIdentifier)
    
    // Critical for iOS 9: Notify the system you've handled the notification
    let settings = UIUserNotificationSettings(types: [.alert, .badge, .sound], categories: nil)
    application.registerUserNotificationSettings(settings)
}

private func displayCustomPushBanner(userInfo: [AnyHashable: Any], targetID: String) {
    let banner = YourThirdPartyBanner()
    // Extract push content from the aps dictionary
    let aps = userInfo["aps"] as? [String: Any] ?? [:]
    let alert = aps["alert"] as? [String: String] ?? [:]
    
    banner.title = alert["title"] ?? ""
    banner.subtitle = alert["body"] ?? ""
    
    // Pass the target VC identifier to the banner
    banner.targetID = targetID
    
    banner.onTap = { [weak self] in
        guard let self = self, !targetID.isEmpty else { return }
        
        // Initialize the target VC using the identifier (adjust if you use storyboards)
        if let vcClass = NSClassFromString(targetID) as? UIViewController.Type {
            let targetVC = vcClass.init()
            
            // Navigate based on your app's root controller
            if let tabBarVC = self.window?.rootViewController as? UITabBarController,
               let selectedNav = tabBarVC.selectedViewController as? UINavigationController {
                selectedNav.pushViewController(targetVC, animated: true)
            } else if let navVC = self.window?.rootViewController as? UINavigationController {
                navVC.pushViewController(targetVC, animated: true)
            } else {
                self.window?.rootViewController?.present(targetVC, animated: true)
            }
        }
    }
    
    banner.show()
}

3. Confirm You're Accessing the Correct Window & Root Controller #

iOS 9 can be finicky with window references. Ensure you're using the active key window to access your root controller:

• Use UIApplication.shared.keyWindow (for iOS 9, this is reliable) instead of assuming a hardcoded window reference.
• If your app uses a UITabBarController as the root, make sure you're pushing to the selected tab's navigation controller (like in the code above).

4. Test if the Tap Event is Actually Triggering #

Add a simple print statement to your banner's tap handler to confirm it's firing:

banner.onTap = {
    print("Custom banner tapped!")
    // Your navigation code here
}

If you don't see this print in the console, the issue is with the banner library's tap binding — check its documentation for iOS 9 compatibility, or try a different library that explicitly supports iOS 9.

5. Double-Check Push Permissions for iOS 9 #

Make sure your app has the correct push permissions enabled in didFinishLaunchingWithOptions:

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    // Request push permissions for iOS 9
    let notificationSettings = UIUserNotificationSettings(types: [.alert, .badge, .sound], categories: nil)
    application.registerUserNotificationSettings(notificationSettings)
    application.registerForRemoteNotifications()
    
    // Rest of your setup code
    return true
}

A final note: iPhone 4s is a 32-bit device running an older iOS version, so some third-party libraries might have dropped iOS 9 support. If all else fails, consider building a simple custom banner component yourself — it's easier to control tap events and navigation logic that way.

内容的提问来源于stack exchange，提问作者kunal kushwaha