是否可以在 tvOS 的 uitabbaritems 上对聚焦和选择状态使用不同的颜色？

Question

在我们的 tvOS 应用程序中，我们有一个自定义的标签栏。现在我们还想更改 focused/selected 项目的背景颜色。当我按 tabBarAppearance.selectionIndicatorTintColor = .purple 执行时，它会将焦点和选定状态更改为紫色（如果没有该行代码，我们确实有不同的颜色或至少不同的不透明度）。

没有自定义颜色：未选择自定义颜色自定义颜色集中选择自定义颜色

是否可以对聚焦和选择使用不同的颜色（就像我对项目文本所做的那样，如您在屏幕截图中所见）？

Answer 1

我通过在 UITabBarController 中每次焦点改变时设置选项卡栏的 standardAppearance 来解决这个问题。相关代码如下所示（外观的初始设置仅为了完整性而发布）：

    // setting up standard appearance for the first time
    private func setupTabbarAppearance() {
        let tabBarAppearance = UITabBarAppearance()
        //...
        tabBarAppearance.selectionIndicatorTintColor = .focusedBackgroundColor // focused items
        //...
        let itemAppearance = UITabBarItemAppearance()
        //...
        itemAppearance.normal.titleTextAttributes[.foregroundColor] = .normalTextColor // used for focused AND non-focused items, 
                                                                                       // when the whole tabbar is focused
        //...
        itemAppearance.selected.titleTextAttributes[.foregroundColor] = .selectedTextColor // used for the selected item,
                                                                                           // wen tabbar is not focused
        // ...
        tabBarAppearance.inlineLayoutAppearance = itemAppearance
        tabBar.standardAppearance = tabBarAppearance
        tabBar.setNeedsLayout()
    }

    private func setTabBarIndicatorColor(tabBarFocused: Bool) {
        let currentAppearance = tabBar.standardAppearance
        // here is where the color is set
        currentAppearance.selectionIndicatorTintColor = tabBarFocused ? .focusedBackgroundColor : .selectedBackgroundColor
        tabBar.standardAppearance = currentAppearance
    }

    // change appearance each time, when focus changes in tabbar controller
    override func didUpdateFocus(in context: UIFocusUpdateContext, with coordinator: UIFocusAnimationCoordinator) {
        if isTabbarInHierarchy(view: context.nextFocusedView) {
            setTabBarIndicatorColor(tabBarFocused: true)
        } else {
            setTabBarIndicatorColor(tabBarFocused: false)
        }
        super.didUpdateFocus(in: context, with: coordinator)
    }

    private func isTabbarInHierarchy(view: UIView?) -> Bool {
        guard let view = view else {return false}
        if view == tabBar {
            return true
        }
        return isTabbarInHierarchy(view: view.superview)
    }

是否可以在 tvOS 的 uitabbaritems 上对聚焦和选择状态使用不同的颜色？

Is it possible to use different colors for focused and selected state on uitabbaritems at tvOS?

uitabbar

tvos

uitabbaritem

uiappearance