如何在应用退到后台时保持 ZEGO SDK 的音视频功能正常运行？

2025-09-28

本文介绍如何在应用退到后台时保持 ZEGO SDK 的音视频功能正常运行。

系统限制

Android 9.0 及以上系统的隐私限制

随着用户对隐私保护要求的提高，Android 9.0 及以后版本对后台应用的音视频权限进行了限制：

麦克风限制
- 应用退后台一分钟后，麦克风将返回静音数据
- 回到前台后会自动恢复，无需额外操作
摄像头限制
- 应用退后台一分钟后，摄像头将被系统释放
- 回到前台后，SDK 会自动恢复摄像头

耗电管理限制

为了优化设备续航能力，Android 9.0 及以上系统增加了后台应用管理功能：

应用退后台一段时间后，系统会限制网络访问
网络受限后，音视频数据无法正常收发
再过一段时间，应用进程可能被系统挂起

对音视频服务的影响

推流端退后台一分钟后:
- 音频和视频数据无法正常发送
- 由于网络限制，与服务器的心跳可能断开
- 拉流端可能收到流删除通知
拉流端退后台后:
- 由于网络限制，无法正常接收音视频数据

解决方案

要让应用在后台保持音视频功能正常运行，可以使用前台服务。以下是具体实现步骤：

1. 声明权限

在 AndroidManifest.xml 中添加前台服务权限：

<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />

<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />

2. 注册服务

在 AndroidManifest.xml 的 application 节点下注册服务：

<application>
    ...
    <service android:name=".ForegroundNotificationService"
    android:foregroundServiceType="microphone"
    android:enabled="true"
    android:exported="false"/>
</application>

<application>
    ...
    <service android:name=".ForegroundNotificationService"
    android:foregroundServiceType="microphone"
    android:enabled="true"
    android:exported="false"/>
</application>

3. 创建前台服务类

public class ForegroundNotificationService extends Service {
    public static final String FOREGROUND_NOTIFICATION_CHANNEL_ID = "foreground_channel_id";
    public static final String FOREGROUND_NOTIFICATION_CHANNEL_NAME = "前台服务通知";
    public static final int FOREGROUND_NOTIFICATION_CHANNEL_IMPORTANCE = NotificationManagerCompat.IMPORTANCE_LOW;
    private static final int FOREGROUND_NOTIFICATION_PENDING_INTENT_REQUEST_CODE = 0x10;
    private static final int FOREGROUND_NOTIFICATION_ID = 0xc000;
    private NotificationManager mNotificationManager;

    @Override
    public void onCreate() {
        super.onCreate();
        mNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        showNotification();
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mNotificationManager.cancel(FOREGROUND_NOTIFICATION_ID);
    }

    private void showNotification() {
        PendingIntent pendingIntent = PendingIntent.getActivity(this,
            FOREGROUND_NOTIFICATION_PENDING_INTENT_REQUEST_CODE,
            new Intent(this, MainActivity.class),
            PendingIntent.FLAG_UPDATE_CURRENT);

        Notification notification = new NotificationCompat.Builder(this, FOREGROUND_NOTIFICATION_CHANNEL_ID)
            .setContentText("应用正在后台运行")
            .setContentIntent(pendingIntent)
            .setSmallIcon(R.drawable.ic_launcher_foreground)
            .build();

        mNotificationManager.notify(FOREGROUND_NOTIFICATION_ID, notification);
        startForeground(FOREGROUND_NOTIFICATION_ID, notification);
    }
}

public class ForegroundNotificationService extends Service {
    public static final String FOREGROUND_NOTIFICATION_CHANNEL_ID = "foreground_channel_id";
    public static final String FOREGROUND_NOTIFICATION_CHANNEL_NAME = "前台服务通知";
    public static final int FOREGROUND_NOTIFICATION_CHANNEL_IMPORTANCE = NotificationManagerCompat.IMPORTANCE_LOW;
    private static final int FOREGROUND_NOTIFICATION_PENDING_INTENT_REQUEST_CODE = 0x10;
    private static final int FOREGROUND_NOTIFICATION_ID = 0xc000;
    private NotificationManager mNotificationManager;

    @Override
    public void onCreate() {
        super.onCreate();
        mNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        showNotification();
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        mNotificationManager.cancel(FOREGROUND_NOTIFICATION_ID);
    }

    private void showNotification() {
        PendingIntent pendingIntent = PendingIntent.getActivity(this,
            FOREGROUND_NOTIFICATION_PENDING_INTENT_REQUEST_CODE,
            new Intent(this, MainActivity.class),
            PendingIntent.FLAG_UPDATE_CURRENT);

        Notification notification = new NotificationCompat.Builder(this, FOREGROUND_NOTIFICATION_CHANNEL_ID)
            .setContentText("应用正在后台运行")
            .setContentIntent(pendingIntent)
            .setSmallIcon(R.drawable.ic_launcher_foreground)
            .build();

        mNotificationManager.notify(FOREGROUND_NOTIFICATION_ID, notification);
        startForeground(FOREGROUND_NOTIFICATION_ID, notification);
    }
}

4. 创建通知渠道

在 Application 类中创建通知渠道：

public class YourApplication extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        createNotificationChannel();
    }

    private void createNotificationChannel() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel(
                ForegroundNotificationService.FOREGROUND_NOTIFICATION_CHANNEL_ID,
                ForegroundNotificationService.FOREGROUND_NOTIFICATION_CHANNEL_NAME,
                ForegroundNotificationService.FOREGROUND_NOTIFICATION_CHANNEL_IMPORTANCE);
            NotificationManager notificationManager = getSystemService(NotificationManager.class);
            notificationManager.createNotificationChannel(channel);
        }
    }
}

public class YourApplication extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        createNotificationChannel();
    }

    private void createNotificationChannel() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel(
                ForegroundNotificationService.FOREGROUND_NOTIFICATION_CHANNEL_ID,
                ForegroundNotificationService.FOREGROUND_NOTIFICATION_CHANNEL_NAME,
                ForegroundNotificationService.FOREGROUND_NOTIFICATION_CHANNEL_IMPORTANCE);
            NotificationManager notificationManager = getSystemService(NotificationManager.class);
            notificationManager.createNotificationChannel(channel);
        }
    }
}

5. 启动和关闭前台服务

在需要保持后台运行的 Activity 中：

public class YourActivity extends AppCompatActivity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        startForegroundNotificationService();
    }

    private void startForegroundNotificationService() {
        startService(new Intent(this, ForegroundNotificationService.class));
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        stopService(new Intent(this, ForegroundNotificationService.class));
    }
}

public class YourActivity extends AppCompatActivity {
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        startForegroundNotificationService();
    }

    private void startForegroundNotificationService() {
        startService(new Intent(this, ForegroundNotificationService.class));
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        stopService(new Intent(this, ForegroundNotificationService.class));
    }
}

注意事项

前台服务需要在通知栏显示持续性通知，这是系统要求
该方案适用于 Android 6.0 及以上版本
即使使用前台服务，仍需遵守系统的隐私限制
建议仅在必要时启用前台服务，以减少电量消耗