轉(zhuǎn)場動畫

以我們常用的present、push轉(zhuǎn)場動畫為例，這種過渡性視圖展示效果被抽象成UIViewControllerAnimatedTransitioning協(xié)議

如下圖敷燎，A present 到B則是調(diào)用系統(tǒng)默認(rèn)的present協(xié)議，自定義轉(zhuǎn)場動畫則是實現(xiàn)UIViewControllerAnimatedTransitioning燥狰，重寫協(xié)議中的動畫對象animator

present的原理.png

tip：當(dāng)B.transitioningDelegate=nil時圈驼，B就會調(diào)用系統(tǒng)默認(rèn)的present協(xié)議

自定義轉(zhuǎn)場動畫

咋們先看看要實現(xiàn)效果，圖標(biāo)有點丑隐圾，勿見怪hah

轉(zhuǎn)場動畫menu.gif

• 實現(xiàn)轉(zhuǎn)場動畫delegate

主要思路：
1困食、使用系統(tǒng)默認(rèn)present轉(zhuǎn)場操作
2、重寫轉(zhuǎn)場協(xié)議翎承，設(shè)置動畫時間硕盹、動畫過渡效果
3、設(shè)置present to 對象的轉(zhuǎn)場協(xié)議為 [步驟2 ]的協(xié)議
4叨咖、run～

協(xié)議實現(xiàn)的工具類如下

import UIKit

class MenuTransitionHepler: NSObject,UIViewControllerAnimatedTransitioning,UIViewControllerTransitioningDelegate {
    
    private var isPresenting = false
    
    //實現(xiàn)UIViewControllerAnimatedTransitioning代理方法
    
    //過場動畫持續(xù)時間
    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
        return 0.5
    }
    
    //過場動畫實現(xiàn)
    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
        
        let container = transitionContext.containerView

        let toVC=transitionContext.viewController(forKey: !self.isPresenting ? UITransitionContextViewControllerKey.from : UITransitionContextViewControllerKey.to)!
        
//        let fromVC=transitionContext.viewController(forKey: !self.isPresenting ? UITransitionContextViewControllerKey.to : UITransitionContextViewControllerKey.from)!
        
//        let fromView    = fromVC.view
        let toView      = toVC.view
        
        //設(shè)置動畫初始位置
        if self.isPresenting {
            self.setOffAnimation(menuVC: toVC as! MenuVC)
        }
        
        container.addSubview(toView!)
        
        let duration = self.transitionDuration(using: transitionContext)

        UIView.animate(withDuration: duration, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 0.8, options: UIViewAnimationOptions.curveLinear, animations: {
            
            if self.isPresenting{
                self.setOnAnimation(menuVC: toVC as! MenuVC)

            }else{
                self.setOffAnimation(menuVC: toVC as! MenuVC)
            }
            
        }, completion: {(finish:Bool) in
            
            transitionContext.completeTransition(true)
            
        })
        

        
        

    }
    
    func offCGAffineTransform(amount:CGFloat) -> CGAffineTransform {
        return CGAffineTransform(translationX: amount, y: 0)
    }
    
    func setOffAnimation(menuVC:MenuVC){
        menuVC.view.alpha = 0
        
        // setup paramaters for 2D transitions for animations
        let topRowOffset  :CGFloat = 300
        let middleRowOffset :CGFloat = 150
        let bottomRowOffset  :CGFloat = 50
        
        menuVC.img_businessCar.transform = self.offCGAffineTransform(amount: -topRowOffset)
        menuVC.l_businessCar.transform = self.offCGAffineTransform(amount: -topRowOffset)
        
        menuVC.img_taxi.transform = self.offCGAffineTransform(amount: topRowOffset)
        menuVC.l_taxi.transform = self.offCGAffineTransform(amount: topRowOffset)
        
        menuVC.img_bus.transform = self.offCGAffineTransform(amount: -middleRowOffset)
        menuVC.l_bus.transform = self.offCGAffineTransform(amount: -middleRowOffset)
        
        menuVC.img_selfDrive.transform = self.offCGAffineTransform(amount: middleRowOffset)
        menuVC.l_selfDrive.transform = self.offCGAffineTransform(amount: middleRowOffset)
        
        menuVC.img_gasStation.transform = self.offCGAffineTransform(amount: -bottomRowOffset)
        menuVC.l_gasStation.transform = self.offCGAffineTransform(amount: -bottomRowOffset)
        
        menuVC.img_service.transform = self.offCGAffineTransform(amount: bottomRowOffset)
        menuVC.l_service.transform = self.offCGAffineTransform(amount: bottomRowOffset)
    }
    
    func setOnAnimation(menuVC:MenuVC){
        menuVC.view.alpha = 1
        
        menuVC.img_businessCar.transform = CGAffineTransform.identity
        menuVC.l_businessCar.transform = CGAffineTransform.identity
        
        menuVC.img_taxi.transform = CGAffineTransform.identity
        menuVC.l_taxi.transform = CGAffineTransform.identity
        
        menuVC.img_bus.transform = CGAffineTransform.identity
        menuVC.l_bus.transform = CGAffineTransform.identity
        
        menuVC.img_selfDrive.transform = CGAffineTransform.identity
        menuVC.l_selfDrive.transform = CGAffineTransform.identity
        
        menuVC.img_gasStation.transform = CGAffineTransform.identity
        menuVC.l_gasStation.transform = CGAffineTransform.identity
        
        menuVC.img_service.transform = CGAffineTransform.identity
        menuVC.l_service.transform = CGAffineTransform.identity
    }
    
    
    //UIViewControllerTransitioningDelegate代理方法
    //presented
    func animationController(forPresented presented: UIViewController, presenting: UIViewController, source: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        self.isPresenting=true
        return self
    }
    
    //dismissed
    func animationController(forDismissed dismissed: UIViewController) -> UIViewControllerAnimatedTransitioning? {
        self.isPresenting=false
        return self
    }
    
    
    
}

to VC里面設(shè)置present代理

 let transitionHelper = MenuTransitionHepler()

    
    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
        self.transitioningDelegate=self.transitionHelper
    }
    

思考

1瘩例、后續(xù)可延伸交互式轉(zhuǎn)場動畫
2、交互式過場動畫是否可作側(cè)滑框架甸各？

demo傳送門垛贤，如果覺得有幫助還望給個star以示支持,thx~
https://github.com/marceChow/-