[iOS]UIView動畫學習筆記(下)

上一篇文章記錄了幾類簡單的動畫內容，下面我們繼續學習更多的動畫，
慕課網視頻的鏈接如下：
http://www.imooc.com/learn/395

本文涉及的內容：
- Repeat
- Easing
- Spring

下面我們分別介紹：

Repeat

可以讓動畫來回動作

override func viewDidAppear(animated: Bool){
    super.viewDidAppear(animated)
    UIView.animateWithDuration(1, animations:{
        self.blueSquare.center.x = self.view.bounds.width - self.blueSquare.center.x
    })
    UIView.animateWithDuration(1, delay:0, options: .Repeat, animations:{
        self.redSquare.center.x = self.view.bounds.width - self.redSquare.center.x
    }, completion: nil)
    UIView.animateWithDuration(1, delay:0, options: .Repeat | .Autoreverse, animations:{
        self.greenSquare.center.x = self.view.bounds.width - self.greenSquare.center.x
    }, completion: nil)

}

Easing

Easing動畫涉及貝塞爾曲線，貝塞爾曲線繪製可以參考如下網址：
http://cubic-bezier.com/
http://easings.net/zh-cn

實現方式如下：

override func viewDidAppear(animated: Bool){
    super.viewDidAppear(animated)
    UIView.animateWithDuration(1, animations:{
        self.blueSquare.center.x = self.view.bounds.width - self.blueSquare.center.x
    })
    UIView.animateWithDuration(1, delay:0, options: .CurveEaseIn, animations:{
        self.redSquare.center.x = self.view.bounds.width - self.redSquare.center.x
    }, completion: nil)
    UIView.animateWithDuration(1, delay:0, options: .CurveEaseOut, animations:{
        self.greenSquare.center.x = self.view.bounds.width - self.greenSquare.center.x
    }, completion: nil)
    UIView.animateWithDuration(1, delay:0, options: .CurveEaseInOut, animations:{
        self.yelloSquare.center.x = self.view.bounds.width - self.yelloSquare.center.x
    }, completion: nil)

}

Spring

Spring彈簧動畫使用的API的參數更多，原型如下：

//只有iOS7以上才支持
UIView.animateWithDuration(duration: NSTimeInterval, 
                           delay: NSTimeInterval,
                           usingSpringWithDamping: CGFloat,
                           initailSpringVelocity: CGFloat,
                           options: UIViewAnimationOptions,
                           animations: () -> Void,
                           completion: ((Bool) -> Void)?)

應用如下：

override func viewDidAppear(animated: Bool){
    super.viewDidAppear(animated)
    UIView.animateWithDuration(1, animations:{
        self.blueSquare.center.x = self.view.bounds.width - self.blueSquare.center.x
    })
    UIView.animateWithDuration(1, delay: 0, usingSpringWithDamping: 0.5, initailSpringVelocity: 0, options: nil, animations:{
        self.redSquare.center.x = self.view.bounds.width - self.redSquare.center.x
},completion: nil)

    UIView.animateWithDuration(5, delay: 0, usingSpringWithDamping:0.3, initailSpringVelocity: 1, options: nil, animations:{
        self.redSquare.center.x = self.view.bounds.width - self.redSquare.center.x
},completion: nil)



}