如何隐藏Apple Watch上iOS关键通知的关闭按钮并留存APNS Payload

Hey there! Let's break down the best solutions for your two questions, based on how Apple's APNS and Notification Framework work with unpaired Apple Watch (since you don't have a Watch App):

a) Removing the "Close" button on Apple Watch notifications #

First off, the straight answer: you can’t directly remove the default "Close" button from Apple Watch notifications, especially for Critical Alerts. This is a system-level default behavior when mirroring iPhone notifications to Apple Watch—Apple automatically provides a dismiss option for high-priority alerts to avoid overwhelming users.

That said, you can tweak the notification’s behavior to reduce reliance on the Close button:

• Use custom notification categories: Define a UNNotificationCategory in your iOS app with custom action buttons (e.g., "Mark as Handled" instead of relying on Close). When sending the APNS payload, specify this category via the category field in the aps dictionary. While the system’s Close button might still appear, custom actions give users an alternative way to interact with the notification, and you can capture payload data when those actions are triggered.
• Adjust alert presentation (if feasible): If your use case allows, switch from a full alert banner to a more subtle presentation, but note that Critical Alerts are designed to be prominent, so this might not work for your key alerts.

Realistically, though, the Close button is unavoidable here. Your better bet is to focus on solving question (b) to ensure payload data isn’t lost when it’s tapped.

b) Ensuring payload access after tapping "Close" #

Here are the most reliable approaches to keep your payload data accessible even after the user closes the notification on Apple Watch:

1. Pre-save payloads locally when the notification arrives #

Add content-available: 1 to your APNS payload (alongside the critical flag). This tells iOS to wake your app in the background when the notification is delivered, even if it’s not running. In your app’s didReceiveRemoteNotification callback, immediately save the payload to local storage (like Core Data, UserDefaults, or Keychain) before any user interaction happens.

Example APNS payload snippet:

{
  "aps": {
    "alert": "Critical Alert!",
    "sound": {
      "critical": 1,
      "name": "default",
      "volume": 1.0
    },
    "content-available": 1
  },
  "custom_data": {
    "your_business_data": "..."
  }
}

Just make sure your iOS app has the Remote notifications background mode enabled in your project settings. This way, even if the user later closes the notification, you already have the payload stored locally.

2. Store payloads on your backend and sync on app launch #

When sending the APNS notification, save a copy of the payload (along with a unique notification_id) to your backend server. Then:

• If the user taps "Close" on Apple Watch, the iPhone’s notification is cleared, but your app can check for unprocessed notifications when it’s next opened or awoken in the background.
• Use the notification_id (included in the APNS payload’s custom fields) to fetch the corresponding data from your backend and sync it to local storage.

3. Capture dismiss events with custom notification categories #

Create a UNNotificationCategory that includes a custom dismiss action. For example:

let dismissAction = UNNotificationAction(identifier: "dismiss.action", title: "Dismiss", options: .destructive)
let category = UNNotificationCategory(identifier: "critical.alert.category", actions: [dismissAction], intentIdentifiers: [], options: .customDismissAction)
UNUserNotificationCenter.current().setNotificationCategories([category])

When sending the APNS payload, set the category field to match your custom category. Now, when the user taps your custom "Dismiss" button (instead of the system’s Close), you’ll get a callback in userNotificationCenter(_:didReceive:withCompletionHandler:), where you can save the payload before dismissing the notification.

Note: The system’s Close button might still appear, but this gives you a way to handle intentional dismissals and preserve data.

4. Listen for notification removal events #

Register to listen for the UNUserNotificationCenter.didRemoveDeliveredNotificationsNotification notification. When this event fires, you’ll get the identifiers of the removed notifications. Use these identifiers to fetch the corresponding payloads from your backend (since you stored them with the notification_id earlier) and sync them to your app.

内容的提问来源于stack exchange，提问作者MadMaxAPP