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

Question

是否有可能使一个UIView焦点？或者我应该UIButton对所有可能的视图使用自定义？

我试图覆盖canBecomeFocused但什么也没发生。

Answer 1

所以问题是我没有注意到我的细胞得到了焦点。要结束这一点，您需要实现

1) 覆盖 canBecomeFocused

2) 覆盖“didUpdateFocusInContext:withAnimationCoordinator:”方法，以便能够将单元格突出显示为焦点

斯威夫特 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)
    }
}

斯威夫特 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)
    }
}

Answer 2

似乎情况发生了变化，现在使视图具有焦点的正确方法是：

override var canBecomeFocused : Bool { return true }

Answer 3

Pavel 代码的 Swift 3 版本：

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)
    }
}