在从容器视图控制器添加/删除时,如何为子视图控制器设置动画？

Question

我有以下2个函数添加和删除从容器视图控制器触发的子视图控制器:

@discardableResult func addChildViewController(withChildViewController childViewController: UIViewController) -> UIViewController {
    // Add Child View Controller
    addChildViewController(childViewController)
    childViewController.beginAppearanceTransition(true, animated: true)
    // Add Child View as Subview
    view.addSubview(childViewController.view)
    // Configure Child View
    childViewController.view.frame = view.bounds
    childViewController.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
    // Notify Child View Controller
    childViewController.didMove(toParentViewController: self)
    return childViewController
}
@discardableResult func removeChildViewController(withChildViewController childViewController: UIViewController) -> UIViewController {
    // Notify Child View Controller
    childViewController.willMove(toParentViewController: nil)
    childViewController.beginAppearanceTransition(false, animated: true)
    // Remove Child View From Superview
    childViewController.view.removeFromSuperview()
    // Notify Child View Controller
    childViewController.removeFromParentViewController()
    return childViewController
}

上面的函数是UIViewController的扩展,所以我所做的只是父视图控制器上的self.addChildViewController()和self.removeChildViewController().

如何为在出路上移除的视图和正在添加的视图添加动画？

Answer 1

addSubview那里缺少Sagar 的答案是不完整的方法

这是完整的答案

func cycleFromViewController(oldViewController: UIViewController, toViewController newViewController: UIViewController) {
        oldViewController.willMove(toParentViewController: nil)
        newViewController.view.translatesAutoresizingMaskIntoConstraints = false

        self.addChildViewController(newViewController)
        self.addSubview(subView: newViewController.view, toView:self.containerView!)

        newViewController.view.alpha = 0
        newViewController.view.layoutIfNeeded()

        UIView.animate(withDuration: 0.5, delay: 0.1, options: .transitionFlipFromLeft, animations: {
            newViewController.view.alpha = 1
            oldViewController.view.alpha = 0
        }) { (finished) in
            oldViewController.view.removeFromSuperview()
            oldViewController.removeFromParentViewController()
            newViewController.didMove(toParentViewController: self)
        }
    }

    //--------------------------------------------------------------------------------


   private func addSubview(subView:UIView, toView parentView:UIView) {
        self.view.layoutIfNeeded()
        parentView.addSubview(subView)

        subView.leadingAnchor.constraint(equalTo: parentView.leadingAnchor).isActive = true
        subView.topAnchor.constraint(equalTo: parentView.topAnchor).isActive = true
        subView.bottomAnchor.constraint(equalTo: parentView.bottomAnchor).isActive = true
        subView.trailingAnchor.constraint(equalTo: parentView.trailingAnchor).isActive  = true
    }

希望对某人有帮助

Answer 2

在不同的子视图控制器之间进行动画处理：-

func cycleFromViewController(oldViewController: UIViewController, toViewController newViewController: UIViewController) {
    oldViewController.willMove(toParentViewController: nil)
    newViewController.view.translatesAutoresizingMaskIntoConstraints = false

    self.addChildViewController(newViewController)
    self.addSubview(subView: newViewController.view, toView:self.containerView!)

    newViewController.view.alpha = 0
    newViewController.view.layoutIfNeeded()

    UIView.animate(withDuration: 0.5, delay: 0.1, options: .transitionFlipFromLeft, animations: { 
        newViewController.view.alpha = 1
        oldViewController.view.alpha = 0
    }) { (finished) in
        oldViewController.view.removeFromSuperview()
        oldViewController.removeFromParentViewController()
        newViewController.didMove(toParentViewController: self)
    }
}

在上面，

• oldViewController：-当前显示的子viewController
• newViewController：-将要添加的新子视图控制器
• containerView：-显示所有子控制器的视图。

若要设置子视图的动画，可以根据需要通过将transitionFlipFromLeft替换为可用的UIViewAnimationOptions来使用不同类型的动画样式。