/// Swaps the display order of two child view controllers within their parent view controller.
///
/// This method is used to adjust the z-ordering of the views associated with two child view controllers.
/// It's particularly useful when the two child view controllers are embedded in a common parent view controller and you want to change which one appears on top.
///
/// - Note:
/// This method will only adjust the order if both view controllers are children of the same parent view controller.
/// If they aren't, the method will have no effect.
///
/// - Parameters:
/// - vc1: The first view controller whose display order you want to swap.
/// - vc2: The second view controller whose display order you want to swap.
///
/// - Usage:
/// Assuming `self` is the parent view controller:
/// ```
/// self.swapViewControllerOrder(childVC1, childVC2)
/// ```
func swapViewControllerOrder<T1: UIViewController, T2: UIViewController>(_ vc1: T1, _ vc2: T2) {
if
let firstIndex = self.children.firstIndex(where: { $0 is T1 }),
let secondIndex = self.children.firstIndex(where: { $0 is T2 }) {
let firstViewFrame = vc1.view.frame
UIView.animate(withDuration: 1, animations: {
vc1.view.frame = vc2.view.frame
vc2.view.frame = firstViewFrame
self.view.exchangeSubview(at: firstIndex, withSubviewAt: secondIndex)
})
}
}
使い方
UIViewControllerのカスタムクラスなどで、
self.swapViewControllerOrder(1つ目のVC, 2つ目のVC)
