Swift play music background

We have an app playing music, if not set play background mode, when screen turn off, music off too. Let add these lines in to viewDidLoad.

do {

tryAVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback)

//print("AVAudioSession Category Playback OK")

do {

tryAVAudioSession.sharedInstance().setActive(true)

// print("AVAudioSession is Active")

            } catchlet error asNSError {

print(error.localizedDescription)

            }

        } catchlet error asNSError {

print(error.localizedDescription)

        }

Click to top folder, choose Capabilities, find Backgroud modes, click to small triangle to show more, click to turn On and check to Audio, Airplay and Picture in Picture.