如何在使用自定义转场时防止键盘消失？

Question

为了在全视图中提供交互弹出手势，我在控制器中使用了UIPanGestureRecognizer，我们可以从视图控制器的任何位置向右滑动以弹出控制器，而不是使用默认的NavigationController弹出手势。

当我在视图中打开键盘时使用手势，键盘也会被关闭（这种情况在使用默认的NavigationController弹出手势时不会发生），看起来很奇怪。

   func navigationController(_ navigationController: UINavigationController, animationControllerFor operation: UINavigationControllerOperation, from fromVC: UIViewController, to toVC: UIViewController) -> UIViewControllerAnimatedTransitioning? {
     if operation == .pop {
        return PopControllerTransition()//My transition
    }
    return nil
}

如何在使用自定义的弹出转场时防止键盘关闭视图控制器。

  //transition code
  func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
    let containerView = transitionContext.containerView
    let fromController = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.from)!
    let toController = transitionContext.viewController(forKey: UITransitionContextViewControllerKey.to)!

    toController.view.transform = CGAffineTransform(translationX: -(toController.view.bounds.width/3), y: 0)
    containerView.insertSubview(toController.view, belowSubview: fromController.view)

    let view = GradientView(frame: containerView.frame)
    view.horizontal = true
    view.backgroundColor = UIColor.clear
    view.transform = CGAffineTransform(translationX: -toController.view.bounds.width, y: 0)
    view.gradientLayer.colors = [UIColor(white: 0.0, alpha: 0.2).cgColor, UIColor(white: 0.0, alpha: 0.5).cgColor]
    containerView.insertSubview(view, belowSubview: fromController.view)

    let duration = transitionDuration(using: transitionContext)

    UIView.animate(withDuration: duration, animations: {
        toController.view.transform = .identity
        fromController.view.transform = CGAffineTransform(translationX: fromController.view.bounds.width, y: 0)
        view.transform = .identity
        view.alpha = 0.0
    }) { (finish) in
        if !transitionContext.transitionWasCancelled {
            fromController.view.removeFromSuperview()
        }
        view.removeFromSuperview()
        transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
    }
}

- Madhu

---

我认为键盘被关闭是因为视图层次结构发生了变化。 - Praveen Kumar

UINavigationController的interactivePopGestureRecognizer没有发生相同的情况。 - Madhu

你能分享一下你的手势处理器吗？ - Aitor Pagán

添加弹出窗口不应该让键盘消失。您可以实现弹出窗口委托来重新打开特定字段的键盘。 - Avijit Nagare

@AvijitNagare 这是使用自定义转场的 popViewController，而不是弹出视图。 - Madhu

Answer 1

我注意到iOS 13上的键盘转换与iOS 12不同，所以我不得不手动进行操作：

    let animations: () -> Void = {
        fromView.frame.origin.x += fromView.bounds.width
        toView.frame.origin.x += fromView.bounds.width

        // Keyboard behavior changed on iOS 13. It dismisses ignoring transition
        // so need to fix that manually.
        if #available(iOS 13.0, *) {
            let keyboardWindow = UIApplication.shared.windows
                .first { String(describing: type(of: $0)) == "UIRemoteKeyboardWindow" }

            if let keyboardWindow = keyboardWindow, let keyboardImage = keyboardWindow.getImage() {
                let imageView = UIImageView(image: keyboardImage)
                keyboardWindow.addSubview(imageView)
                keyboardWindow.frame.origin.x += keyboardWindow.frame.width
            }
        }
    }

你可以查看我所做的实现 - https://github.com/APUtils/Animators/blob/master/Animators/Classes/Right%20Slide%20Animation/RightSlideOutAnimator.swift

- Anton Plebanovich