終于空閑下來了缓窜，如今花一些時(shí)間學(xué)習(xí)我喜歡的動(dòng)畫吻育。
今天著重研究UIViewAnimationOptions

1. 動(dòng)畫重復(fù)（Repeating）

.repeat: 讓動(dòng)畫一直重復(fù)執(zhí)行

.autoreverse: 配合.repeat使用捻激，使動(dòng)畫反轉(zhuǎn)并持續(xù)執(zhí)行

2. 動(dòng)畫緩和（Animation easing）

.linear: 讓動(dòng)畫保持勻速

.curveEaseIn: 在動(dòng)畫開始時(shí)加速

.curveEaseOut: 在動(dòng)畫結(jié)束時(shí)減速

.curveEaseInOut: 相當(dāng)于[.curveEaseIn, .curveEaseOut]的組合，在開始加速和在結(jié)束動(dòng)畫時(shí)減速

3. 彈性動(dòng)畫（Spring animations）

// 方法展現(xiàn)與參數(shù)分析
UIView.animate(withDuration: 0.5, delay: 0.5, usingSpringWithDamping: 0.5, initialSpringVelocity: 0.0, options: [], animations: {
      self.loginButton.center.y -= 30
      self.loginButton.alpha = 1.0
    }, completion: nil)

? usingSpringWithDamping: 設(shè)置彈性動(dòng)畫的阻尼(范圍：0.0～1.0)栅组，越接近0.0彈性越大宴猾，反之則越小。
? initialSpringVelocity: 控制動(dòng)畫初始速度抵乓。

4. 轉(zhuǎn)換動(dòng)畫（Transitions）

轉(zhuǎn)換動(dòng)畫選項(xiàng)列表

.transitionFlipFromLeft, // 從左邊翻轉(zhuǎn)
.transitionFlipFromRight, // 從右邊翻轉(zhuǎn)
.transitionFlipFromTop, // 從底部翻轉(zhuǎn)
.transitionFlipFromBottom, // 從底部翻轉(zhuǎn)
.transitionCurlUp, // 卷上去
.transitionCurlDown, // 卷下來
.transitionCrossDissolve // 交叉溶解

增加一個(gè)視圖（Adding a new view）

var animationContainerView: UIView?

  override func viewDidLoad() {
    super.viewDidLoad()
    animationContainerView = UIView(frame: view.bounds)
    view.addSubview(animationContainerView!)
  }
  override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    
  }
  override func viewDidAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    // create new view
    let newView = UIImageView()
    
    newView.image = UIImage(named: "e50")
    newView.frame.size = CGSize(width: 50, height: 50)
    newView.center = animationContainerView!.center

    // add the new view via transition
    UIView.transition(with: animationContainerView!,
                      duration: 0.33,
                      options: [.curveEaseOut, .transitionFlipFromBottom],
                      animations: { self.animationContainerView?.addSubview(newView) },
                      completion: nil)
  }

移除一個(gè)視圖（Removing a view）

  // remove the view via transition
  UIView.transition(with: newView,
                    duration: 0.33,
                    options: [.curveEaseOut, .transitionFlipFromBottom],
                    animations: { self.newView.removeFromSuperview() },
                    completion: nil)

隱藏／顯示一個(gè)視圖（Hiding/showing a view）

  // hide the view via transition
  UIView.transition(with: self.newView,
                    duration: 0.33,
                    options: [.curveEaseOut, .transitionFlipFromBottom],
                    animations:{ self.newView.isHidden = true },
                    completion: nil)

替換一個(gè)視圖（Replacing a view with another view）

  注意事項(xiàng)伴挚，需要設(shè)置新視圖frame靶衍，即大小和位置。
  // replace via transition
  UIView.transition(from: newView,
                    to: oldView,
                    duration: 0.33,
                    options: .transitionFlipFromTop,
                    completion: nil)

5. 關(guān)鍵幀動(dòng)畫（Keyframe animations）

UIViewKeyframeAnimationOptions選項(xiàng)如下：

  .calculationModeLinear, // 連續(xù)運(yùn)算模式茎芋，線性
  .calculationModeDiscrete, // 離散運(yùn)算模式颅眶，只顯示關(guān)鍵幀
  .calculationModePaced, // 均勻執(zhí)行運(yùn)算模式，線性
  .calculationModeCubic, // 平滑運(yùn)算模式
  .calculationModeCubicPaced // 平滑均勻運(yùn)算模式

11月-14-2016 18-33-21.gif

demo

  func planeDepart() {
    // 記錄初始位置
    let originalCenter = planeImage.center
    // 設(shè)置動(dòng)畫總時(shí)間為1.5秒, options動(dòng)畫
    UIView.animateKeyframes(withDuration: 1.5, delay: 0.0, options: [], animations: {
      // add keyframes
      // 下面使用的事件都是相對事件（相對于當(dāng)前1.5s）田弥，范圍為(0.0~0.1)
      UIView.addKeyframe(withRelativeStartTime: 0.0, relativeDuration: 0.25, animations: {
        self.planeImage.center.x += 80.0
        self.planeImage.center.y -= 10.0
      })

      UIView.addKeyframe(withRelativeStartTime: 1.0, relativeDuration: 0.4, animations: {
        self.planeImage.transform = CGAffineTransform(rotationAngle: .pi * 0.125)
      })

      UIView.addKeyframe(withRelativeStartTime: 0.25, relativeDuration: 0.25, animations: {
        self.planeImage.center.x += 100.0
        self.planeImage.center.y -= 50
        self.planeImage.alpha = 0.0
      })

      UIView.addKeyframe(withRelativeStartTime: 0.51, relativeDuration: 0.01, animations: {
        self.planeImage.transform = CGAffineTransform.identity
        self.planeImage.center = CGPoint(x: 0.0, y: originalCenter.y)
      })

      UIView.addKeyframe(withRelativeStartTime: 0.55, relativeDuration: 0.45, animations: {
        self.planeImage.alpha = 1.0
        self.planeImage.center = originalCenter
      })
      
    }, completion: nil)

  }