UIButton没有在两个图像Swift 4.2之间切换

Question

I am wanting to add sounds to my app. I have added a UIButton with two images, soundON and soundOFF. When I call the sound settings in the app the first time, they toggle fine with each image. However, when I return to the sound settings a second and subsequent time, it is like the soundOff images does not disappear when the soundOn image is displayed. Odd as the code is so short and simple.

func soundButton() {
    sounds = UIButton(frame : CGRect(x: 65, y: 70, width: 40, height:40))
    sounds.setImage(UIImage(named : "soundON"), for : .normal)
    sounds.setImage(UIImage(named : "soundOFF"), for : .selected)
    sounds.showsTouchWhenHighlighted = true
    sounds.addTarget(self, action: #selector(soundButtonTapped), for: .touchUpInside)
    self.soundView.addSubview(sounds)
}

@objc func soundButtonTapped(_ sender: Any) {
    sounds.isSelected.toggle()
    isSoundOn.toggle()
}

I have added a video to show the issue as this will save a ton of typing.

http://www.reeflifeapps.com/soundError.mov

Any help is greatly appreciated.

update: I had the button on a UIView that was hidden on startup of the puzzle. When the user pressed the "Sounds Settings" icon, the sound setting UIView was unhidden. I had the button on this func to unhide the sound settings. I moved it to viewDidLoad() and it fixed it.

Answer 1

I suggest you to define a boolean variable that keeps the current state of your button. Then, you should set current image of button according to the current state of the variable.

var isSoundOn = false

@objc func soundButtonTapped(_ sender: Any) {
    isSoundOn.toggle()
    if isSoundOn {
        // your logic when sound on (set button selected image, action etc)
    } else {
        // logic when sound off (set button not selected image, action etc)
    }
}

If you still want to use soundButton.isSelected as your boolean variable,do not define images for different states in soundButton.setImage(yourImage, for: .selected) and soundButton.setImage(yourImage, for: .normal) and define them as follows:

soundButton.setImage(soundButton.isSelected ? soundOnImage : soundOffImage, for: .normal)

One of those two approaches above can be used.

UPDATE:

As Lloyd Kaijzer stated, isSoundOn = !isSoundOn updated as isSoundOn.toggle()