avplayer has no sounds when play video

Question

here is all my codes for play a mp4,the mp4 is playing but no sounds out

import UIKit

import AVFoundation
class ViewController: UIViewController {

@IBOutl         


        

Answer 1

I had multiple view controllers that needed to play audio even when the device what set to mute. So instead of updating every single viewDidLoad, I added the following to the didFinishLaunchingWithOptions method in the AppDelegate.swift file.

try? AVAudioSession.sharedInstance().setCategory(AVAudioSession.Category.playback)

Notes:

• import AVFoundation
• I didn't need any other error catching so I just used try?.
• I am supporting down to iOS 9. Gang Fang's answer required iOS 10. Only using the single parameter as I did above, though, worked fine for iOS 9.
• Tested with Swift 5