Refactor: switch to native download notification

android/app/src/main/AndroidManifest.xml

@@ -7,7 +7,7 @@
         android:extractNativeLibs="true">
         <meta-data
              android:name="io.flutter.embedding.android.EnableImpeller"
-             android:value="false" 
+             android:value="false"
         />
         <activity
             android:name=".MainActivity"
@@ -35,11 +35,13 @@
         <meta-data
             android:name="flutterEmbedding"
             android:value="2" />
-        <!-- flutter_foreground_task service -->
         <service
-            android:name="com.pravera.flutter_foreground_task.service.ForegroundService"
-            android:foregroundServiceType="dataSync"
-            android:exported="false" />
+                android:name=".DownloadForegroundService"
+                android:foregroundServiceType="dataSync"
+                android:exported="false" />
+        <receiver
+                android:name=".DownloadNotificationActionReceiver"
+                android:exported="false" />
     </application>
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />

android/app/src/main/kotlin/com/example/kazumi/DownloadForegroundService.kt

@@ -0,0 +1,144 @@
+package com.example.kazumi
+
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.PendingIntent
+import android.app.Service
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+import android.os.IBinder
+import androidx.core.app.NotificationCompat
+
+class DownloadForegroundService : Service() {
+
+    companion object {
+        const val CHANNEL_ID = "kazumi_download_channel"
+        const val CHANNEL_NAME = "下载服务"
+        const val NOTIFICATION_ID = 10086
+
+        const val ACTION_START = "kazumi.action.DOWNLOAD_START"
+        const val ACTION_UPDATE = "kazumi.action.DOWNLOAD_UPDATE"
+        const val ACTION_STOP = "kazumi.action.DOWNLOAD_STOP"
+
+        const val EXTRA_TITLE = "title"
+        const val EXTRA_TEXT = "text"
+        const val EXTRA_PROGRESS = "progress"
+        const val EXTRA_INDETERMINATE = "indeterminate"
+
+        fun start(context: Context, title: String, text: String) {
+            val i = Intent(context, DownloadForegroundService::class.java).apply {
+                action = ACTION_START
+                putExtra(EXTRA_TITLE, title)
+                putExtra(EXTRA_TEXT, text)
+                putExtra(EXTRA_PROGRESS, 0)
+                putExtra(EXTRA_INDETERMINATE, true)
+            }
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) context.startForegroundService(i)
+            else context.startService(i)
+        }
+
+        fun update(context: Context, title: String, text: String, progress: Int, indeterminate: Boolean = false) {
+            val i = Intent(context, DownloadForegroundService::class.java).apply {
+                action = ACTION_UPDATE
+                putExtra(EXTRA_TITLE, title)
+                putExtra(EXTRA_TEXT, text)
+                putExtra(EXTRA_PROGRESS, progress.coerceIn(0, 100))
+                putExtra(EXTRA_INDETERMINATE, indeterminate)
+            }
+            context.startService(i)
+        }
+
+        fun stop(context: Context) {
+            val i = Intent(context, DownloadForegroundService::class.java).apply { action = ACTION_STOP }
+            context.startService(i)
+        }
+    }
+
+    override fun onCreate() {
+        super.onCreate()
+        ensureChannel()
+    }
+
+    override fun onBind(intent: Intent?): IBinder? = null
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        when (intent?.action) {
+            ACTION_START -> {
+                val title = intent.getStringExtra(EXTRA_TITLE) ?: "正在下载"
+                val text = intent.getStringExtra(EXTRA_TEXT) ?: "准备中..."
+                val progress = intent.getIntExtra(EXTRA_PROGRESS, 0)
+                val indeterminate = intent.getBooleanExtra(EXTRA_INDETERMINATE, true)
+                startForeground(NOTIFICATION_ID, buildNotification(title, text, progress, indeterminate))
+            }
+
+            ACTION_UPDATE -> {
+                val title = intent.getStringExtra(EXTRA_TITLE) ?: "正在下载"
+                val text = intent.getStringExtra(EXTRA_TEXT) ?: ""
+                val progress = intent.getIntExtra(EXTRA_PROGRESS, 0)
+                val indeterminate = intent.getBooleanExtra(EXTRA_INDETERMINATE, false)
+                val nm = getSystemService(NOTIFICATION_SERVICE) as NotificationManager
+                nm.notify(NOTIFICATION_ID, buildNotification(title, text, progress, indeterminate))
+            }
+
+            ACTION_STOP -> {
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) stopForeground(STOP_FOREGROUND_REMOVE)
+                else {
+                    @Suppress("DEPRECATION")
+                    stopForeground(true)
+                }
+                stopSelf()
+            }
+        }
+        return START_NOT_STICKY
+    }
+
+    private fun buildNotification(title: String, text: String, progress: Int, indeterminate: Boolean): Notification {
+        val openIntent = Intent(this, MainActivity::class.java).apply {
+            addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP or Intent.FLAG_ACTIVITY_CLEAR_TOP)
+            action = MainActivity.ACTION_OPEN_DOWNLOAD_MANAGER
+        }
+
+        val pendingFlags =
+            PendingIntent.FLAG_UPDATE_CURRENT or (if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) PendingIntent.FLAG_IMMUTABLE else 0)
+
+        val openPendingIntent = PendingIntent.getActivity(this, 0, openIntent, pendingFlags)
+
+        val pauseIntent = Intent(this, DownloadNotificationActionReceiver::class.java).apply {
+            action = DownloadNotificationActionReceiver.ACTION_PAUSE_ALL
+        }
+        val pausePending = PendingIntent.getBroadcast(this, 1, pauseIntent, pendingFlags)
+
+        val builder = NotificationCompat.Builder(this, CHANNEL_ID)
+            .setSmallIcon(android.R.drawable.stat_sys_download)
+            .setContentTitle(title)
+            .setContentText(text)
+            .setContentIntent(openPendingIntent)
+            .setOngoing(true)
+            .setOnlyAlertOnce(true)
+            .setShowWhen(false)
+            .setProgress(100, progress.coerceIn(0, 100), indeterminate)
+            .setPriority(NotificationCompat.PRIORITY_LOW)
+            .addAction(0, "暂停全部", pausePending)
+
+        // Android 12+：更及时显示
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+            builder.setForegroundServiceBehavior(NotificationCompat.FOREGROUND_SERVICE_IMMEDIATE)
+        }
+
+        return builder.build()
+    }
+
+    private fun ensureChannel() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val nm = getSystemService(NOTIFICATION_SERVICE) as NotificationManager
+            val ch = NotificationChannel(CHANNEL_ID, CHANNEL_NAME, NotificationManager.IMPORTANCE_LOW).apply {
+                description = "视频下载后台服务"
+                setSound(null, null)
+                enableVibration(false)
+            }
+            nm.createNotificationChannel(ch)
+        }
+    }
+}

android/app/src/main/kotlin/com/example/kazumi/DownloadNotificationActionReceiver.kt

@@ -0,0 +1,22 @@
+package com.example.kazumi
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+
+class DownloadNotificationActionReceiver : BroadcastReceiver() {
+
+    override fun onReceive(context: Context, intent: Intent) {
+        val action = intent.action ?: return
+
+        // 先落地，避免 Flutter 不在时丢事件
+        val sp = context.getSharedPreferences("kazumi_download", Context.MODE_PRIVATE)
+        sp.edit().putString("pending_action", action).apply()
+
+        MainActivity.dispatchDownloadActionToFlutter(action)
+    }
+
+    companion object {
+        const val ACTION_PAUSE_ALL = "kazumi.action.PAUSE_ALL"
+    }
+}