一、简单的动画
1、闭包
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2、commit方法形式
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二、重要属性及方法介绍
1、transform
继承自CGAffineTransform属性，是核心动画框架与UIView之间的桥梁，借助这个属性可实现缩放、旋转、位移.
缩放动画 btn!.transform = CGAffineTransform(scaleX: 0.7, y: 1.2)
上述方法表明宽高变成原来的额0.7和1.2倍
旋转动画 btn!.transform = CGAffineTransform(rotationAngle: CGFloat(M_PI_4))
位移动画 btn!.transform = CGAffineTransform(translationX: 0, y: 40)（是相对于原来的位置移动多少）
2.动画常用属性
open class func beginAnimations(_ animationID: String?, context: UnsafeMutableRawPointer?)
open class func commitAnimations()
open class func setAnimationDelegate(_ delegate: Any?)
open class func setAnimationWillStart(_ selector: Selector?)
open class func setAnimationDidStop(_ selector: Selector?)
open class func setAnimationDuration(_ duration: TimeInterval)
open class func setAnimationDelay(_ delay: TimeInterval)
open class func setAnimationStart(_ startDate: Date)
open class func setAnimationCurve(_ curve: UIView.AnimationCurve)
open class func setAnimationRepeatCount(_ repeatCount: Float)
open class func setAnimationRepeatAutoreverses(_ repeatAutoreverses: Bool)
open class func setAnimationBeginsFromCurrentState(_ fromCurrentState: Bool)
open class func setAnimationTransition(_ transition: UIView.AnimationTransition, for view: UIView, cache: Bool)
open class func setAnimationsEnabled(_ enabled: Bool)
open class var areAnimationsEnabled: Bool { get }
如 UIView.setAnimationDuration(2)设置动画执行时间
其他的属性都好懂，具体介绍下setAnimationCurve，该方法用于动画加速、减速，对应的是一个枚举值
public enum AnimationCurve : Int {
case easeInOut //表示动画在开始和结束都呈减速
case easeIn //开始时呈减速
case easeOut // 结束时呈加速
case linear //速度一直一样
}
setAnimationRepeatAutoreverses //表示是否具有返回效果
3、动画结束的额回调方法
1)设置代理方法：暂时没有找到，不知道是不是废弃了
2）自定义回调方法
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
UIView.beginAnimations(nil, context: nil)
UIView.setAnimationDuration(2)
//此处实现代理
UIView.setAnimationDelegate(self)
//此处设置回调方法
UIView.setAnimationDidStop(#selector(ViewController.AnimationDidStop(btn:)))
btn!.transform = CGAffineTransform(scaleX: 0.7, y: 1.2)
btn!.transform = CGAffineTransform(translationX: 100, y: 100)
UIView.commitAnimations()
}
@objc func AnimationDidStop(btn:UIButton){
print("动画结束了")
}
三、关键帧动画
1、关键帧动画的核心方法如下
open class func animateKeyframes(withDuration duration: TimeInterval, delay: TimeInterval, options: UIView.KeyframeAnimationOptions = [], animations: @escaping () -> Void, completion: ((Bool) -> Void)? = ni
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2、第二个方法，添加中间帧数
open class func addKeyframe(withRelativeStartTime frameStartTime: Double, relativeDuration frameDuration: Double, animations: @escaping () -> Void)
frameStartTime ： 表示整个动画的哪个点开始
relativeDuration ： 占整个动画的时间比
animations ： 动画实现的内容
实现代码
@objc func btnClick(){
UIView.animateKeyframes(withDuration: 2, delay: 1, options: UIView.KeyframeAnimationOptions.calculationModeCubic, animations: {()in
UIView.addKeyframe(withRelativeStartTime: 0, relativeDuration: 1/2, animations: {
self.btn!.frame = CGRect(x: 300, y: 200, width: 60, height: 60)
})
UIView.addKeyframe(withRelativeStartTime: 1/2, relativeDuration: 1/2, animations: {
self.btn!.frame = CGRect(x: 300, y: 600, width: 80, height: 80)
})
}) { (finish) in
}
}
四、显示层逐帧动画（动画效果就是将图片一帧帧逐帧渲染）
1、利用Timer和displayLink，重复个ImageView服不同的值
2、利用view的draw方法，不停的调用setNeedDisplay,来调用draw方法进行重绘
class MyView1: UIView {
var blackHelloReadis:Float = 0
func blackHelloIncrease(_ readis:Float){
blackHelloReadis = readis
self.setNeedsDisplay()
}
override func draw(_ rect: CGRect) {
let ctx:CGContext = UIGraphicsGetCurrentContext()!
ctx.addArc(center: self.center, radius:CGFloat(blackHelloReadis), startAngle: 0, endAngle: CGFloat(Double.pi*2), clockwise: false)
ctx.fillPath()
}
}
class MyController1: UIViewController {
var index:CGFloat = 0.0
var time:Timer?
var backV:MyView1?
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor.white
let myCv = MyView1()
myCv.frame = self.view.bounds
myCv.center = view.center
myCv.backgroundColor = UIColor.cyan
view.addSubview(myCv)
backV = myCv
time = Timer.scheduledTimer(timeInterval: 0.1, target:self, selector: #selector(add), userInfo: nil, repeats: true)
}
@objc func add(){
backV?.blackHelloIncrease(Float(index))
index = index + 0.1
}
}
以上时利用draw方法绘制一个逐渐变大的圆
五、gif图片的处理
核心框架---ImageIO
1、gif的分解，具体过程如下
94CC9258-A67F-4C78-9B85-D8CE94800F7C.png
将gif图分解成一张张图片的过程代码如下：
func getGifImage() {
//获取gif路径
let gifPath:NSString = Bundle.main.path(forResource: "timg", ofType: "gif")! as NSString
//获取二进制数据
let gifData:Data = try! Data(contentsOf: URL(fileURLWithPath: gifPath as String))
let gifDataSource:CGImageSource = CGImageSourceCreateWithData(gifData as CFData, nil)!
let gifImageCount:Int = CGImageSourceGetCount(gifDataSource)
for i in 0...gifImageCount-1 {
let imageref:CGImage? = CGImageSourceCreateImageAtIndex(gifDataSource, i, nil)
let im:UIImage = UIImage(cgImage: imageref!, scale: UIScreen.main.scale, orientation: UIImage.Orientation.up)
let imageData:NSData = im.pngData()! as NSData
var docs = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
let doucmentDic = docs[0] as String
let imagePath = doucmentDic + "/\(i)" + ".png"
try?imageData.write(to:URL(fileURLWithPath: imagePath), options: .atomic)
}
}
2、gif图片的合成
未完待续...