如何在tvOS中获得UIButton的视差效果

Question

我正在尝试在 tvOS 应用程序的UIView中制作一些UIButtons，但无法让他们在模拟器中显示新的视差效果。我成功地在images.xcassets中设置了一个名为"startReadingButton"的电视图像堆栈，我的按钮随文件一起加载，但是在模拟器中的遥控器上滑动时，它们没有显示闪亮的视差效果。以下是我加载UIButtons的方式：

   for button in 1...5 {
        let image = UIImage(named: "startReadingButton")
        let newButton = UIButton(type: .Custom)
        newButton.frame = buttonRects[button - 1]
        newButton.setBackgroundImage(image, forState: UIControlState.Focused)
        newButton.imageView?.image = image
        newButton.imageView?.adjustsImageWhenAncestorFocused = true
        newButton.addTarget(self, action: "buttonPressed:", forControlEvents: UIControlEvents.PrimaryActionTriggered)
        newButton.tag = button
        newButton.canBecomeFocused()
        newButton.adjustsImageWhenHighlighted = true
        newButton.clipsToBounds = false
        self.addSubview(newButton)
        self.homeButtons.append(newButton)
    }

到目前为止，我已经尝试了几乎所有我能想到的变体来找到解决方案，例如将按钮类型设置为两者。自定义和 .系统，在UIButton的不同参数中设置图像等。但是，我无法让按钮进入视差模式并在聚焦时四处移动。

有谁知道我需要做什么才能获得所需的视差效果？

Answer 1

解决了我的问题 -

在UIButton的setImage属性中将 LSR 或 Apple TV 图像堆栈设置为UIControlState.Focused状态。

在UIButton上设置imageView?.clipsToBounds = false。

在UIButton上设置newButton.imageView?.adjustsImageWhenAncestorFocused = true。

我有以下代码按预期工作：

  for button in 1...3 {
        let buttonUnpressedTexture = UIImage(contentsOfFile:NSBundle.mainBundle().resourcePath!.stringByAppendingPathComponent("startReadingUnpressed.png"))!
        let buttonPressedTexture = UIImage(contentsOfFile:NSBundle.mainBundle().resourcePath!.stringByAppendingPathComponent("startReadingPressed.png"))!
        let newButton = UIButton(type: .Custom)
        newButton.frame = buttonRects[button - 1]
        newButton.setImage(buttonUnpressedTexture, forState: UIControlState.Normal)
        newButton.setImage(buttonPressedTexture, forState: UIControlState.Highlighted)
        newButton.setImage(UIImage(named: "StartReadingButton"), forState: UIControlState.Focused)
        newButton.imageView?.clipsToBounds = false
        newButton.imageView?.adjustsImageWhenAncestorFocused = true
        newButton.addTarget(self, action: "buttonPressed:", forControlEvents: UIControlEvents.PrimaryActionTriggered)
        newButton.tag = button
        newButton.canBecomeFocused()
        self.addSubview(newButton)            
    }

"StartReadingButton"是我的images.xcassets目录中的Apple TV图像堆栈。