I am programatically creating a UIView subview of a UIScrollView. The scrollview is black, and I want to set a subview's background's alpha to different values so that different shades of grey show through.
let frame = CGRect(x:0, y:92*position, width:320, height:92)
let view = UIView(frame:frame)
var alpha:CGFloat = 1.0
for _ in 0 ... position { alpha = 3*alpha/4 }
view.layer.backgroundColor = UIColor(red:128, green:128, blue:128, alpha:alpha).cgColor
view.layer.isOpaque = false
With this code, the subview's background is always white. It makes no difference if I set view.backgroundColor and view.isOpaque instead of using the CALayer. Any help greatly appreciated.
Steve.
I see 2 problems :
- you ned to add the subview to the scroll view
scrollView.addSubview(view)where scrollView is the IBOutlet you have declared
- In UIColor : parameters must be between 0 and 1.
With 128, it is just as if you said 1 : hence it is all white.
Change to
UIColor(red:0.5, green:0.5, blue:0.5, alpha:alpha)With these 2 changes, I tested, it works.
Note: you should better rename view (too generic) and call it for instance insideView
