Flutter应用点击C#推送通知无法启动问题排查及正确Payload配置咨询

Hey there, let's break down why your push notification isn't launching your Flutter app when clicked, even though you've set up the FLUTTER_NOTIFICATION_CLICK intent filter. Here are the likely issues and fixes:

Possible Root Causes #

1. Invalid badge Field Value #

Your current payload sets badge to a link, but Android expects a numeric value (e.g., 1) for the app icon badge. A non-numeric value here can cause notification parsing errors, which might prevent the click action from triggering correctly.

2. Missing Android-Specific Notification Configuration #

Firebase Cloud Messaging (FCM) often requires explicit Android-specific settings to ensure the notification launches your app properly. Your current payload only uses the top-level notification object, which might not be enough in some cases.

3. Incomplete Payload Structure #

While click_action is present, combining it with a data payload can help Flutter handle the notification click more reliably, especially if you need to pass additional data to the app.

Correct C# Payload Format #

Here's a fixed payload that addresses the above issues and ensures the notification launches your app:

Basic Working Payload #

var payload = new
{
    notification = new
    {
        icon = "your_icon_link",
        badge = 1, // Numeric value for Android badge
        title = "New Notification",
        body = "Message here",
        click_action = "FLUTTER_NOTIFICATION_CLICK",
        renotify = true
    },
    data = new
    {
        // Optional: Add any custom data you want to pass to the app
        screen = "home",
        messageId = "12345"
    },
    android = new
    {
        priority = "high",
        notification = new
        {
            click_action = "FLUTTER_NOTIFICATION_CLICK"
        }
    }
};

Key Improvements: #

• Changed badge to a numeric value (required for Android)
• Added an android object to explicitly set the click action for Android devices
• Included a data object (optional but recommended) to support deeper app navigation or data passing

Additional Checks #

1. Verify AndroidManifest.xml: Double-check that your intent filter is placed inside the <activity> tag that launches your app (usually the main Flutter activity):

   <activity
       android:name=".MainActivity"
       android:exported="true">
       <intent-filter>
           <action android:name="FLUTTER_NOTIFICATION_CLICK" />
           <category android:name="android.intent.category.DEFAULT" />
       </intent-filter>
       <!-- Your existing launcher intent filter -->
       <intent-filter>
           <action android:name="android.intent.action.MAIN" />
           <category android:name="android.intent.category.LAUNCHER" />
       </intent-filter>
   </activity>
   

   Note: Using DEFAULT category instead of LAUNCHER for the FLUTTER_NOTIFICATION_CLICK action is more appropriate, as it allows the activity to be launched from the notification without conflicting with the launcher intent.

2. Flutter Firebase Messaging Setup: Ensure you're handling notification clicks in your Flutter code using the firebase_messaging package:

   FirebaseMessaging.onMessageOpenedApp.listen((RemoteMessage message) {
       // Handle the notification click, e.g., navigate to a specific screen
       print('Notification clicked!');
   });
   

This should resolve the issue where clicking the notification doesn't launch your app. Test this payload and let me know if you run into any further issues!

内容的提问来源于stack exchange，提问作者Dinesh