How to change volume programmatically on iOS 11.4

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深忆病人
深忆病人 2021-01-17 18:52

Before, I was setting sound volume programmatically using this approach:

MPVolumeView *volumeView = [[MPVolumeView alloc] init];
UISlider *volumeViewSlider =         


        
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  • 2021-01-17 19:27

    I solved it by adding new MPVolumeView to my UIViewController view, otherwise it didn't set the volume anymore. As I added it to the controller I also need to set the volume view position to be outside of the screen to hide it from the user.

    I prefer not to use delayed volume setting as it make things more complicated especially if you need to play sound immediately after setting the volume.

    The code is in Swift 4:

    let volumeControl = MPVolumeView(frame: CGRect(x: 0, y: 0, width: 120, height: 120))
    
    override func viewDidLoad() {
       self.view.addSubview(volumeControl);
    }
    
    override func viewDidLayoutSubviews() {
       volumeControl.frame = CGRect(x: -120, y: -120, width: 100, height: 100);
    }
    
    func setVolume(_ volume: Float) {
        let lst = volumeControl.subviews.filter{NSStringFromClass($0.classForCoder) == "MPVolumeSlider"}
        let slider = lst.first as? UISlider
    
        slider?.setValue(volume, animated: false)
    }
    
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  • 2021-01-17 19:36

    Changing volumeViewSlider.value after a small delay resolves problem.

    - (IBAction)increase:(id)sender {
      MPVolumeView *volumeView = [[MPVolumeView alloc] init];
      UISlider *volumeViewSlider = nil;
    
      for (UIView *view in volumeView.subviews) {
        if ([view isKindOfClass:[UISlider class]]) {
          volumeViewSlider = (UISlider *)view;
          break;
        }
      }
    
      dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.01 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        volumeViewSlider.value = 0.5f;
      });
    }
    

    Swift version

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  • 2021-01-17 19:45

    I had to have a MPVolumeView as subview to a view in the hierarchy for the hud not to show up on iOS 12. It needs to be slightly visible:

    let volume = MPVolumeView(frame: .zero)
    volume.setVolumeThumbImage(UIImage(), for: UIControl.State())
    volume.isUserInteractionEnabled = false
    volumelume.alpha = 0.0001
    volume.showsRouteButton = false
    view.addSubview(volume)
    

    When setting the volume I get the slider from MPVolumeView as with previous posters and set the value:

    func setVolumeLevel(_ volumeLevel: Float) {
        guard let slider = volume.subviews.compactMap({ $0 as? UISlider }).first else {
            return
        }
    
        slider.value = volumeLevel
    }
    
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  • 2021-01-17 19:47

    I just added the MPVolumeView as a subview to another view (that was never drawn on screen).

    This had to be done prior to any attempt to set or get the volume.

    private let containerView = UIView()
    private let volumeView = MPVolumeView()
    
    func prepareWorkaround() {
        self.containerView.addSubview(self.volumeView)
    }
    
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