Swift将透明颜色添加到UIImageView背景

Question

var controllerScreen   = UIImageView()
controllerScreen.backgroundColor = UIColor.redColor()

This adds red opaque color to the UIImageView. I want to add a transparent red color. Is there any transparent property or something ?

Answer 1

作为@ AdamPro13答案的替代方法，您可以执行以下操作：

controllerScreen.backgroundColor = UIColor.redColor().colorWithAlphaComponent(0.5)

Answer 2

You need to change the alpha value of the red color. You can use something like this: UIColor(red: 1.0, green: 0.0, blue: 0.0, alpha: 0.5)