Swift 自定义弹出控制器

项目中会经常使用一些弹出的View如果直接在控制器的View中写会照成里面的代码太多了，所以我们要自定义一个弹出的控制器。一些逻辑处理在我们自定义的控制器里面做， 要自定义大小
我们自定义一个控制器, 名字叫做PopoverViewController

//2.设置弹出控制器
       let popoverView = PopoverViewController()
       //3.设置弹出动画 防止x底下的控制器的vView被移除
       popoverView.modalPresentationStyle = .custom
       popoverView.transitioningDelegate = self
       present(popoverView, animated: true, completion: nil)

现在他可以弹出来，但是大小是占据整个屏幕的额
我们要控制它的大小，
首先，modal出的控制器，都有一个父控制器来暂时存放UIPresentationController

extension HomeTVC : UIViewControllerTransitioningDelegate
{
    func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController?
    {
    return WBPresentationController(presentedViewController: presented, presenting: presenting)
    }
    
}

自定义一个UIPresentationController，手动调整里面的被弹出的控制器，和弹出的控制器

import UIKit

class WBPresentationController: UIPresentationController
{

    //从新布局
    override func containerViewWillLayoutSubviews()
    {
        //设置弹出试图的尺寸
        presentedView?.frame = CGRect(x: 100, y: 55, width: 180, height: 200)
        addCoverView()
    }
    
}

//MARK: - 设置UI相关 -
extension WBPresentationController
{
    private func addCoverView()
    {
        let coverView = UIView();
        coverView.backgroundColor = UIColor(white: 0.5, alpha: 0.6)
        coverView.frame = containerView!.bounds
        containerView?.insertSubview(coverView, at: 0)
        
        //添加手势
        let tap = UITapGestureRecognizer(target: self, action: #selector(coverViewClick))
        coverView.addGestureRecognizer(tap)
    }
}

//MARK: - 事件监听 -
extension WBPresentationController
{
    @objc private func coverViewClick()
    {
        presentedViewController.dismiss(animated: true, completion: nil)
    }
}

自定义弹出动画。逐渐变大

要遵守UIViewControllerAnimatedTransitioning协议

extension PopoverAnimator : UIViewControllerTransitioningDelegate
{
    func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController?
    {
    return WBPresentationController(presentedViewController: presented, presenting: presenting)
    }
    // 目的:自定义弹出的动画
    func  animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning?
    {
        isPresented = true
        return self
    }
    func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning?
    {
        isPresented = false
        return self
    }
}

extension PopoverAnimator : UIViewControllerAnimatedTransitioning
{
     /// 动画执行的时间
    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval
    {
        return 0.3
    }
    /// 获取`转场的上下文`:可以通过转场上下文获取弹出的View和消失的View
       // UITransitionContextFromViewKey : 获取消失的View
       // UITransitionContextToViewKey : 获取弹出的View
    func animateTransition(using transitionContext: UIViewControllerContextTransitioning)
    {
        isPresented ? animatForPresentedView(transitionContext: transitionContext) : animatForDismissedView(transitionContext: transitionContext)
    }
    
    /// 自定义弹出动画
     private func animatForPresentedView(transitionContext: UIViewControllerContextTransitioning)
    {
        // 1.获取弹出的View
        let presentView = transitionContext.view(forKey: UITransitionContextViewKey.to)!
        
        // 2.将弹出的View添加到containerView中
        transitionContext.containerView.addSubview(presentView)
        
        //3.知行动画
        presentView.transform = CGAffineTransform(scaleX: 1.0, y: 0)
        presentView.layer.anchorPoint = CGPoint(x: 0.5, y: 0)

        UIView.animate(withDuration: transitionDuration(using: transitionContext), animations:
        {
            presentView.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)
        })
        { (_) in
            //告诉上下文 完成动画
            transitionContext.completeTransition(true)
        }
    }
    
    /// 自定义消失动画
    private func animatForDismissedView(transitionContext: UIViewControllerContextTransitioning)
    {
      // 1.获取弹出的View
        let presentView = transitionContext.view(forKey: UITransitionContextViewKey.from)!
        
        // 2.将弹出的View添加到containerView中
        transitionContext.containerView.addSubview(presentView)
        
        //3.知行动画

        UIView.animate(withDuration: transitionDuration(using: transitionContext), animations:
        {
            presentView.transform = CGAffineTransform(scaleX: 1.0, y: 0.00001)
        })
        { (_) in
            //告诉上下文 完成动画
            transitionContext.completeTransition(true)
        }
    }
    
}