Question

我想在iOS中创建一个原子动画动画，但有些麻烦无法解决。 here is my animation result

CAKeyframeAnimation 位置动画与 CABasicAnimation strokeEnd动画不匹配（粒子动画与其尾迹动画不匹配）。

2.尾流动画循环不连贯， CABasicAnimation 似乎不能代表冲程段，即strokeStart为正且strokeEnd为负。

我的代码：

    let atom = CAShapeLayer()
    var rect = CGRect(x: 0,y: 0,width: 5,height: 5)
    var path = UIBezierPath(roundedRect: rect,cornerRadius: 5.0)

    atom.path = path.CGPath;
    atom.strokeColor = UIColor.greenColor().CGColor
    atom.bounds = rect;
    rect = CGRect(x: 0,y: 0,width: 300,height: 50);
    path = UIBezierPath(ovalInRect:rect);



    let orbit = CAShapeLayer()
    orbit.path = path.CGPath;
    orbit.strokeColor = UIColor.whiteColor().CGColor
    orbit.lineWidth = 1;
    orbit.fillColor = UIColor.clearColor().CGColor
    orbit.bounds = CGPathGetPathBoundingBox(path.CGPath);
    orbit.position = CGPoint(x:150,y:25)

    rect = CGRect(x: 0,y: 0,width: 300,height: 50);
    path = UIBezierPath(ovalInRect:rect);


    let keyani = CAKeyframeAnimation(keyPath: "position");
    keyani.path = path.CGPath
    keyani.duration = 3.0;
    keyani.repeatCount = HUGE;
    keyani.additive = true
    keyani.calculationMode = kCAAnimationPaced
    keyani.rotationMode = kCAAnimationRotateAuto


    keyani.timingFunction = CAMediaTimingFunction(name:kCAMediaTimingFunctionLinear);
    atom.addAnimation(keyani, forKey: "")


    let orbitAni = CABasicAnimation(keyPath: "strokeStart")
    orbitAni.byValue = 1.0
    orbitAni.cumulative = true


    let orbitAni1 = CABasicAnimation(keyPath: "strokeEnd")
    orbitAni1.fromValue = 0.0
    orbitAni1.toValue = 1.0

    let animationGroup = CAAnimationGroup()
    animationGroup.animations = [orbitAni,orbitAni1]
    animationGroup.duration = 3.0
    animationGroup.repeatCount = HUGE


    orbit.strokeStart = -0.2
    orbit.addAnimation(animationGroup, forKey: "");
    orbit.shadowRadius = 5.0;
    orbit.shadowColor = UIColor.greenColor().CGColor
    orbit.shadowOpacity = 0.5
    orbit.shadowOffset = CGSizeZero

    var trans = CGAffineTransformIdentity
    trans = CGAffineTransformRotate(trans, CGFloat(M_PI_4))

    repeator.instanceTransform = CATransform3DMakeAffineTransform (trans)
    repeator.instanceCount = 4;
    repeator.instanceDelay = 0;
    repeator.addSublayer(orbit)
    repeator.addSublayer(atom)
    repeator.bounds = CGRect(x: 0,y: 0,width: 300,height: 50)
    repeator.position = CGPoint(x:200,y:200)
    repeator.anchorPoint = CGPoint(x:0.5,y:0.5)
    repeator.instanceAlphaOffset = 1.0

如何控制strokeEnd动画线速度

0 个答案: