iOS开发之UIBezierPath曲线动画

func animation1(layerParam: CAShapeLayer){
        let animation = CABasicAnimation(keyPath: "strokeStart")
        animation.fromValue = 0
        animation.toValue = 1
        animation.duration = 2.0
        layerParam.addAnimation(animation, forKey: "")
    }

这段代码可以用来实现曲线的绘制动画，fromValue和toValue分别表示动画起始点和终点，0代表startPoint，1代表endPoint，整条路径可以看成单位1，0.5之类的中间值也是可以的。别忘了把函数添加

self.animation1(layer)

忽略那个鼠标吧。。。。。。

还可以写成中间向两边的效果

func animation2(layerParam: CAShapeLayer){
        layerParam.strokeStart = 0.5
        layerParam.strokeEnd = 0.5

        let animation1 = CABasicAnimation(keyPath: "strokeStart")
        animation1.fromValue = 0.5
        animation1.toValue = 0
        animation1.duration = 2

        let animation2 = CABasicAnimation(keyPath: "strokeEnd")
        animation2.fromValue = 0.5
        animation2.toValue = 1
        animation2.duration = 2

        layerParam.addAnimation(animation1, forKey: "")
        layerParam.addAnimation(animation2, forKey: "")

    }

配合lineWidth可以得到下面效果

func animation3(layerParam: CAShapeLayer){
        let animation = CABasicAnimation(keyPath: "lineWidth")
        animation.fromValue = 1
        animation.toValue = 10
        animation.duration = 2
        layerParam.addAnimation(animation, forKey: "")
    }

圆形矩形什么都可以实现。