Jetpack Compose（无Fragment）结合导航图处理FCM通知后台跳转

在Jetpack Compose无Fragment的项目里，处理后台FCM通知点击跳转，核心是利用FCM的消息字段配置和Activity的Intent数据传递，分两种场景实现：

一、利用FCM默认通知的内置跳转逻辑 #

当应用处于后台时，FCM的通知消息（包含notification字段）会由系统托盘直接展示，要实现点击跳转指定页面，需在发送FCM消息时同时携带data字段，将订单ID这类关键数据放入其中。

示例FCM消息结构： #

{
  "to": "设备令牌",
  "notification": {
    "title": "订单状态更新",
    "body": "您的订单12345已发货"
  },
  "data": {
    "order_id": "12345",
    "screen": "order_detail"
  }
}

在主Activity中处理Intent数据： #

主Activity是Compose导航的入口，需在Activity中读取Intent携带的data字段，触发Compose导航跳转：

class MainActivity : ComponentActivity() {
    private val navController by lazy { rememberNavController() }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        handleNotificationData(intent)
        setContent {
            YourAppTheme {
                NavHost(navController = navController, startDestination = "home") {
                    composable("home") { HomeScreen(navController) }
                    composable("order_detail/{orderId}") { backStackEntry ->
                        val orderId = backStackEntry.arguments?.getString("orderId") ?: ""
                        OrderDetailScreen(orderId)
                    }
                }
            }
        }
    }

    // 单Task模式下，后台点击通知会触发此方法
    override fun onNewIntent(intent: Intent?) {
        super.onNewIntent(intent)
        intent?.let { handleNotificationData(it) }
    }

    private fun handleNotificationData(intent: Intent) {
        val orderId = intent.getStringExtra("order_id")
        val targetScreen = intent.getStringExtra("screen")
        if (targetScreen == "order_detail" && orderId != null) {
            // 避免重复跳转
            if (navController.currentDestination?.route != "order_detail/$orderId") {
                navController.navigate("order_detail/$orderId")
            }
        }
    }
}

注意：给主Activity设置singleTop或singleTask启动模式，避免重复创建实例，确保onNewIntent能接收到通知的Intent。

二、自定义本地通知实现完全控制 #

如果需要更灵活的通知样式或跳转逻辑，可忽略FCM默认通知，在FirebaseMessagingService中自行构建本地通知，用PendingIntent指定跳转，和本地通知逻辑完全一致：

1. 自定义FirebaseMessagingService： #

class MyFirebaseMessagingService : FirebaseMessagingService() {
    override fun onMessageReceived(remoteMessage: RemoteMessage) {
        super.onMessageReceived(remoteMessage)
        // 提取消息数据
        val orderId = remoteMessage.data["order_id"] ?: ""
        val title = remoteMessage.notification?.title ?: "订单通知"
        val body = remoteMessage.notification?.body ?: ""

        // 创建跳转Intent
        val intent = Intent(this, MainActivity::class.java).apply {
            putExtra("order_id", orderId)
            putExtra("screen", "order_detail")
            flags = Intent.FLAG_ACTIVITY_CLEAR_TOP or Intent.FLAG_ACTIVITY_SINGLE_TOP
        }
        val pendingIntent = PendingIntent.getActivity(
            this,
            0,
            intent,
            PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
        )

        // 构建并发送通知
        val notification = NotificationCompat.Builder(this, "order_channel")
            .setContentTitle(title)
            .setContentText(body)
            .setSmallIcon(R.drawable.ic_notification)
            .setContentIntent(pendingIntent)
            .setAutoCancel(true)
            .build()

        NotificationManagerCompat.from(this).notify(1, notification)
    }
}

2. 配置Service清单： #

在AndroidManifest.xml中注册自定义Service：

<service
    android:name=".MyFirebaseMessagingService"
    android:exported="false">
    <intent-filter>
        <action android:name="com.google.firebase.MESSAGING_EVENT" />
    </intent-filter>
</service>

这种方式无论应用处于前台还是后台，都能完全控制通知的展示和跳转逻辑，和本地通知实现逻辑一致。

内容的提问来源于stack exchange，提问作者vanste25