Android 通过使用通知和前台服务来实现锁屏音乐控制

1. 创建前台服务

首先，创建一个前台服务来管理音乐播放：

class MusicService : Service() {

    override fun onCreate() {
        super.onCreate()
        createNotificationChannel()
        startForeground(1, createNotification())
    }

    private fun createNotificationChannel() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            val channel = NotificationChannel(
                "music_channel",
                "Music Channel",
                NotificationManager.IMPORTANCE_LOW
            )
            val manager = getSystemService(NotificationManager::class.java)
            manager.createNotificationChannel(channel)
        }
    }

    private fun createNotification(): Notification {
        return NotificationCompat.Builder(this, "music_channel")
            .setContentTitle("Music Player")
            .setContentText("Playing music")
            .setSmallIcon(R.drawable.ic_music_note)
            .setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
            .build()
    }

    override fun onBind(intent: Intent?): IBinder? {
        return null
    }
}

2. 启动前台服务

在你的 Activity 中启动前台服务：

val intent = Intent(this, MusicService::class.java)
startService(intent)

3. 创建自定义通知

你可以创建一个自定义通知布局来控制音乐播放：

private fun createNotification(): Notification {
    val remoteViews = RemoteViews(packageName, R.layout.notification_layout)

    val playIntent = Intent(this, MusicService::class.java).apply {
        action = "ACTION_PLAY"
    }
    val playPendingIntent = PendingIntent.getService(this, 0, playIntent, 0)
    remoteViews.setOnClickPendingIntent(R.id.play_button, playPendingIntent)

    return NotificationCompat.Builder(this, "music_channel")
        .setContent(remoteViews)
        .setSmallIcon(R.drawable.ic_music_note)
        .setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
        .build()
}

4. 处理广播接收器

在 MusicService 中处理广播接收器来控制播放、暂停等操作：

class MusicService : Service() {

    private val receiver = object : BroadcastReceiver() {
        override fun onReceive(context: Context?, intent: Intent?) {
            when (intent?.action) {
                "ACTION_PLAY" -> {
                    // 处理播放操作
                }
                "ACTION_PAUSE" -> {
                    // 处理暂停操作
                }
            }
        }
    }

    override fun onCreate() {
        super.onCreate()
        createNotificationChannel()
        startForeground(1, createNotification())
        registerReceiver(receiver, IntentFilter().apply {
            addAction("ACTION_PLAY")
            addAction("ACTION_PAUSE")
        })
    }

    override fun onDestroy() {
        super.onDestroy()
        unregisterReceiver(receiver)
    }

    // 其他代码...
}

5. 锁屏显示通知

确保通知在锁屏时显示：

private fun createNotification(): Notification {
    return NotificationCompat.Builder(this, "music_channel")
        .setContentTitle("Music Player")
        .setContentText("Playing music")
        .setSmallIcon(R.drawable.ic_music_note)
        .setVisibility(NotificationCompat.VISIBILITY_PUBLIC) // 锁屏时显示
        .build()
}