更改UINavigationController 的转换需要使用的是在堆栈中找到第一个UIViewController。您应该将此UIViewController 扩展为UIViewControllerTransitioningDelegate 和UINavigationControllerDelegate。
然后,您可以调用func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationController.Operation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? 来定义您想要呈现新的UIViewControllers 的过渡类型。
因此,为了做到这一点,我们必须创建一个自定义的UIViewControllerAnimatedTransitioning 类并在这个UIViewControllerTransitioningDelegate 方法中返回它。这是我使用的示例。
import UIKit
class SimpleOver: NSObject, UIViewControllerAnimatedTransitioning {
var direction: TransitionDirection!
init(direction: TransitionDirection) {
self.direction = direction
}
var popStyle: Bool = false
func transitionDuration(
using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
return 0.20
}
func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
if popStyle {
animatePop(using: transitionContext)
return
}
let fz = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.from)!
let tz = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.to)!
let f = transitionContext.finalFrame(for: tz)
let fOff = f.offsetBy(dx: f.width, dy: 0)
tz.view.frame = fOff
transitionContext.containerView.insertSubview(tz.view, aboveSubview: fz.view)
UIView.animate(
withDuration: transitionDuration(using: transitionContext),
animations: {
tz.view.frame = f
for subview in fz.view.subviews {
subview.alpha = 0
}
}, completion: {_ in
transitionContext.completeTransition(true)
})
}
func animatePop(using transitionContext: UIViewControllerContextTransitioning) {
let fz = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.from)!
let tz = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.to)!
let f = transitionContext.initialFrame(for: fz)
let fOffPop = f.offsetBy(dx: f.width, dy: 0)
transitionContext.containerView.insertSubview(tz.view, belowSubview: fz.view)
UIView.animate(
withDuration: transitionDuration(using: transitionContext),
animations: {
fz.view.frame = fOffPop
for subview in tz.view.subviews {
subview.alpha = 1
}
}, completion: {_ in
transitionContext.completeTransition(true)
})
}
}
enum TransitionDirection {
case left
case right
}
然后,在我们的func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationController.Operation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? 方法中,我们可以简单地返回这个UIViewControllerAnimatedTransitioning:
extension YourViewController: UIViewControllerTransitioningDelegate, UINavigationControllerDelegate {
func navigationController(
_ navigationController: UINavigationController,
animationControllerFor operation: UINavigationController.Operation,
from fromVC: UIViewController,
to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
//This tells our navigation controller the style that we want to animate our transition between view controllers
let simpleOver = SimpleOver(direction: .right)
simpleOver.popStyle = (operation == .pop)
return simpleOver
}
}