How do you change UIButton image alpha on disabled state?

Question

I have a UIButton with an image and on its disabled state, this image should have .3 alpha.

UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
UIIm         


        

Answer 1

Swift 5:

Here's a solution that extends the UIButton class. No need to sub-class. In my example, button alpha is set to 0.55 if .isEnabled is false, and 1.0 if it's true.

extension UIButton {

override open var isEnabled: Bool{
    didSet {
        self.alpha = isEnabled ? 1.0 : 0.55
    }
}

}