ios8自定义转场动画
-
首先只能在iOS 8后使用
默认情况下modal会移除以前控制器的view, 替换为当前弹出的view
如果自定义转场, 那么就不会移除以前控制器的view
// vc是要被model的控制器
let vc = UIViewController()
// 设置转场代理为当前控制器
vc?.transitioningDelegate = self
// 设置转场的样式为自定义
vc?.modalPresentationStyle = UIModalPresentationStyle.custom
present(vc!, animated: true, completion: nil)
1.遵守UIViewControllerTransitioningDelegate协议，实现协议方法， 设置转场样式为自定义
@available(iOS 8.0, *)
optional public func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController?
2.要返回一个UIPresentationController,所以自顶一个类继承UIPresentationController
class CustomPopoverPresentationController: UIPresentationController {
/**
初始化方法, 用于创建负责转场动画的对象
:param: presentedViewController 被展现的控制器
:param: presentingViewController 发起的控制器, Xocde6是nil, Xcode7是野指针
:returns: 负责转场动画的对象
*/
override init(presentedViewController: UIViewController, presenting presentingViewController: UIViewController?) {
super.init(presentedViewController: presentedViewController, presenting: presentingViewController)
}
/**
即将布局转场子视图时调用
*/
override func containerViewWillLayoutSubviews()
{
// presentedView 表示为弹出的视图，containerView 表示容器view
// 1.修改弹出视图的大小
presentedView?.frame = CGRect(x: 100, y: 56, width: 200, height: 200)
// 2.在容器视图上添加一个蒙版, 插入到展现视图的下面
containerView?.insertSubview(coverView, at: 0)
}
// MARK: - 懒加载
fileprivate lazy var coverView: UIView = {
// 1.创建view
let view = UIView()
view.backgroundColor = UIColor(white: 0.0, alpha: 0.2)
view.frame = UIScreen.main.bounds
// 2.添加监听
let tap = UITapGestureRecognizer(target: self, action: "close")
view.addGestureRecognizer(tap)
return view
}()
func close(){
// presentedViewController拿到当前弹出的控制器
presentedViewController.dismiss(animated: true, completion: nil)
}
}
3.返回的UIPresentationController就用自定义类创建
func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController?
{
return CustomPopoverPresentationController(presentedViewController: presented, presenting: presenting)
}
4.实现协议中另外两个方法来自定义动画的实现
只要实现了以下方法, 那么系统自带的默认动画就没有了, "所有"东西都需要程序员自己来实现
自定义一个isPresent表示是否model出来了
@available(iOS 2.0, *) // 即将弹出
optional public func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning?
@available(iOS 2.0, *) // 即将消失
optional public func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning?
/**
告诉系统谁来负责Modal的展现动画
:param: presented 被展现视图
:param: presenting 发起的视图
:returns: 谁来负责
*/
func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning?
{
isPresent = true
return self
}
/**
告诉系统谁来负责Modal的消失动画
:param: dismissed 被关闭的视图
:returns: 谁来负责
*/
func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning?
{
isPresent = false
return self
}
5.由于UIViewControllerAnimatedTransitioning是协议，而设置了当前控制器遵守协议，所以需要遵守协议实现方法，如下遵守UIViewControllerAnimatedTransitioning协议 ，实现方法
public func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval
// This method can only be a nop if the transition is interactive and not a percentDriven interactive transition.
public func animateTransition(using transitionContext: UIViewControllerContextTransitioning)
// 实现方法
// MARK: - UIViewControllerAnimatedTransitioning
/**
返回动画时长
:param: transitionContext 上下文, 里面保存了动画需要的所有参数
:returns: 动画时长
*/
func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval
{
return 0.5
}
/**
告诉系统如何动画, 无论是展现还是消失都会调用这个方法
:param: transitionContext 上下文, 里面保存了动画需要的所有参数
*/
func animateTransition(using transitionContext: UIViewControllerContextTransitioning)
{
// 1.拿到展现视图
/*
let toVC = transitionContext.viewControllerForKey(UITransitionContextToViewControllerKey)
let fromVC = transitionContext.viewControllerForKey(UITransitionContextFromViewControllerKey)
// 通过打印发现需要修改的就是toVC上面的View
print(toVC)
print(fromVC)
*/
if isPresent
{
// 展开
print("展开")
let toView = transitionContext.view(forKey: UITransitionContextViewKey.to)!
toView.transform = CGAffineTransform(scaleX: 1.0, y: 0.0);
// 注意: 一定要将视图添加到容器上
transitionContext.containerView.addSubview(toView)
// 设置锚点
toView.layer.anchorPoint = CGPoint(x: 0.5, y: 0)
// 2.执行动画
UIView.animate(withDuration: 0.5, animations: { () -> Void in
// 2.1清空transform
toView.transform = CGAffineTransform.identity
}, completion: { (_) -> Void in
// 2.2动画执行完毕, 一定要告诉系统
// 如果不写, 可能导致一些未知错误
transitionContext.completeTransition(true)
})
}else
{
// 关闭
print("关闭")
let fromView = transitionContext.view(forKey: UITransitionContextViewKey.from)
UIView.animate(withDuration: 0.2, animations: { () -> Void in
// 注意:由于CGFloat是不准确的, 所以如果写0.0会没有动画
// 压扁
fromView?.transform = CGAffineTransform(scaleX: 1.0, y: 0.000001)
}, completion: { (_) -> Void in
// 如果不写, 可能导致一些未知错误
transitionContext.completeTransition(true)
})
}
}