ExoPlayer stops playing in background

问题

I have an application that keeps a global instance of an ExoPlayer instance to facilitate audio streams in the background. After opening lots of apps, the audio stops playing.

It happens as follows:

• open Activity that starts playing audio
• press back button to close Activity
• the audio is still playing and keeps doing so if you leave the device alone (as intended)

However, when you open a dozen or more apps after the last step, the ExoPlayer stops playing at some point. My guess is that a memory cleanup happens and thus ExoPlayer gets deallocated. I tried to get more information from the logs, but that has provided little help so far.

Keeping a reference of the ExoPlayer inside an android.app.Service doesn't make a difference.

The device I am testing on is a Nexus 5 with Android 5.1.x, but the issue happens on other devices too.

I couldn't find a solution in the ExoPlayer documentation pages nor on StackOverflow or Google. Does anyone know the correct way to prevent the ExoPlayer from stopping playback?

回答1:

To make sure a Service stays alive as much as possible without being killed by the system, you need to make sure you start it as a foreground service.

This means there will be a notification informing the user of the active service so he can be aware of it. Because of that, you must start the service with a corresponding notification. Here is the example from the docs:

Notification notification = new Notification(R.drawable.icon, getText(R.string.ticker_text),
            System.currentTimeMillis()); 
Intent notificationIntent = new Intent(this, ExampleActivity.class); 
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0); 
notification.setLatestEventInfo(this, getText(R.string.notification_title),
            getText(R.string.notification_message), pendingIntent); 
startForeground(ONGOING_NOTIFICATION_ID, notification);

来源：https://stackoverflow.com/questions/34400026/exoplayer-stops-playing-in-background