不调用preferredFocusEnvironments

Question

preferredFocusEnvironments 不会被嵌入到容器视图中的视图控制器调用

对于这些情况还有什么额外的事情要做吗？

Answer 1

你需要覆盖父视图控制器的var preferredFocusEnvironments: [UIFocusEnvironment]：

override var preferredFocusEnvironments: [UIFocusEnvironment] { return [childViewController] }