如何阻止应用被杀死时通知栏默认通知，及自定义通知时默认通知弹出？

Hey there! Let's work through these two notification problems you're dealing with—they're super common when building custom notification flows, so I've got actionable steps for each one:

1. Stop Default Notifications When the App Is Killed #

That unwanted default notification usually pops up because of how Android handles background/foreground services, or in some cases, manufacturer-specific behavior. Here's how to fix it:

• Check for accidental foreground service setup: If your app doesn't need to run as a foreground service (which requires a notification by default on Android 8.0+), make sure you're not calling startForeground() anywhere in your service code. That method forces a notification to be displayed to let users know a service is running.
• Use a silent notification channel for necessary foreground services: If you do need a foreground service (e.g., for ongoing tasks like location tracking), you can make its notification invisible to users. Create a notification channel with minimum importance, then use that channel for your foreground service notification:

  // Create a silent notification channel
  val channelId = "silent_foreground_channel"
  val channel = NotificationChannel(
      channelId,
      "Silent Background Service",
      NotificationManager.IMPORTANCE_MIN
  ).apply {
      description = "Hidden notification for background tasks"
      setShowBadge(false)
      enableVibration(false)
      enableLights(false)
  }
  
  // Register the channel
  val notificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
  notificationManager.createNotificationChannel(channel)
  
  // Build and start foreground service with this channel
  val silentNotification = NotificationCompat.Builder(this, channelId)
      .setSmallIcon(R.drawable.ic_your_icon)
      .setContentTitle("Background task running")
      .setPriority(NotificationCompat.PRIORITY_MIN)
      .build()
  
  startForeground(123, silentNotification)
  

• Handle manufacturer-specific behavior: Some brands (like Xiaomi, Huawei, or Samsung) add their own default notifications when apps are killed. For these, you'll need to guide users to disable system-level notifications for your app: have them go to Settings > Apps > [Your App] > Notifications and turn off any system-generated notification categories.

2. Block Default Notifications When Using zzE to Generate Custom Notifications #

If your custom notification is appearing alongside a default one, the issue is likely that another part of your code (or the system) is triggering a second notification. Try these fixes:

• Audit the zzE method: Check if this method is inadvertently calling system notification APIs or relying on default templates. Make sure when you build your custom notification, you're explicitly setting your own notification channel, content, and icon—don't leave any fields that might fall back to system defaults.
• Cancel existing default notifications before showing your custom one: If the default notification is coming from a background service or system trigger, cancel it first using the NotificationManager:

  val notificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
  // Cancel a specific default notification by ID (replace with the actual ID used)
  notificationManager.cancel(DEFAULT_NOTIFICATION_ID)
  // Or cancel all notifications if you're sure none of yours will be affected
  // notificationManager.cancelAll()
  

• Avoid triggering foreground service requirements: If your background data receiver is causing the system to promote your service to foreground (thus generating a default notification), switch to using modern background task APIs like WorkManager instead of raw services. WorkManager handles background task scheduling without forcing foreground notifications unless absolutely necessary.

Hope these tips help you eliminate those annoying default notifications! If you run into specific code issues or need clarification on any step, feel free to share more details.

内容的提问来源于stack exchange，提问作者Umar Farooq