swift - 如何使用 Apple TV 上的焦点引擎使 UIView 可聚焦

Question

是否可以使 UIView 可聚焦？或者我应该为所有可能的 View 使用自定义 UIButton 吗？

我试图覆盖 canBecomeFocused 但没有任何反应。

Answer 1

所以问题是我没有注意到我的手机获得了焦点。总结一下，您需要实现

1) 覆盖 canBecomeFocused

2) 重写“didUpdateFocusInContext:withAnimationCoordinator:”方法以突出显示焦点单元格

swift 2.3:

override func canBecomeFocused() -> Bool {
    return true
}

override func didUpdateFocusInContext(context: UIFocusUpdateContext, withAnimationCoordinator coordinator: UIFocusAnimationCoordinator) {

    if context.nextFocusedView == self {
        coordinator.addCoordinatedAnimations({ () -> Void in
            self.layer.backgroundColor = UIColor.blueColor().colorWithAlphaComponent(0.2).CGColor
        }, completion: nil)
    } else if context.previouslyFocusedView == self {
        coordinator.addCoordinatedAnimations({ () -> Void in
            self.layer.backgroundColor = UIColor.clearColor().CGColor
        }, completion: nil)
    }
}

swift 3:

override var canBecomeFocused: Bool {
    return true
}

override func didUpdateFocus(in context: UIFocusUpdateContext, with coordinator: UIFocusAnimationCoordinator) {
    if context.nextFocusedView == self {
        coordinator.addCoordinatedAnimations({ () -> Void in
            self.layer.backgroundColor = UIColor.blue.withAlphaComponent(0.2).cgColor
        }, completion: nil)

    } else if context.previouslyFocusedView == self {
        coordinator.addCoordinatedAnimations({ () -> Void in
            self.layer.backgroundColor = UIColor.clear.cgColor
        }, completion: nil)
    }
}