将图像添加到蒙版图层（CALayer）内的按钮上？

Question

I have a button inside a CALayer and cannot find a way to add an image to it.

Here is my code. The button appears but....

        let button1 = UIButton(type: UIButtonType.Custom) as UIButton
        button1.frame = CGRectMake(36, 100 , 36, 36)
        button1.addTarget(self, action: "Action:", forControlEvents: UIControlEvents.TouchUpInside)

         // Create your mask layer

        let maskLayer: CALayer = CALayer()
        maskLayer.frame = CGRectMake(0, 0, 250, 150)
        maskLayer.backgroundColor = UIColor.clearColor().CGColor
        maskLayer.addSublayer(button1.layer)
        maskLayer.contents = (UIImage(named: "RedDot.png")!.CGImage as! AnyObject)

        // Apply the mask to your uiview layer

        infoWindow.layer.addSublayer(maskLayer)



        return infoWindow

Answer 1

Since you are trying to add button's layer as sublayer setting image to the button doesn't work. One way is to set layer content as below,

    button1.layer.contents = (UIImage(named: "image.png")!.CGImage as! AnyObject)

In this way you can't set other properties like pressed state etc.