我一直在用
Swift制作一个简单的UIBezierPath动画.该路径包括创建带有彩色边框的圆角矩形.动画必须是彩色边框的绘图.为此,我创建了一个带有UIBezierPath(roundedRect :,cornerRadius：)的CAShapeLayer
let layer = CAShapeLayer()
var viewPrueba = UIView()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view,typically from a nib.
viewPrueba = UIView(frame: CGRectMake(self.view.frame.width/2-100,self.view.frame.height/2 - 100,200,200))
self.view.addSubview(viewPrueba)
let path = UIBezierPath(roundedRect: CGRectMake(0,200),cornerRadius: 40.0)
layer.path = path.CGPath
layer.fillColor = UIColor.clearColor().CGColor
layer.strokeColor = UIColor.blueColor().CGColor
layer.strokeStart = 0.0
layer.strokeEnd = 0.0
layer.lineWidth = 4.0
layer.lineJoin = kCALineJoinRound
viewPrueba.layer.addSublayer(layer)
let tapGR = UITapGestureRecognizer(target: self,action: #selector(ViewController.anim))
self.view.addGestureRecognizer(tapGR)
}
func anim() {
let anim1 = CABasicAnimation(keyPath: "strokeEnd")
anim1.fromValue = 0.0
anim1.toValue = 1.0
anim1.duration = 4.0
anim1.repeatCount = 0
anim1.autoreverses = false
anim1.removedOnCompletion = false
anim1.additive = true
anim1.fillMode = kCAFillModeForwards
self.layer.addAnimation(anim1,forKey: "strokeEnd")
}`
它工作得很好唯一的问题是动画从广场的左上角开始,而不是从顶部中心开始.我怎样才能做到这一点？
为了实现这一点,我发现唯一的事情是用一个圆圈而不是一个矩形,这不是我们想要的.
谢谢
解决方法
CoreAnimate动画与UIBezierPath绘制的顺序相同.
系统方法
系统方法
+ (instancetype)bezierPathWithRoundedRect:(CGRect)rect cornerRadius:(CGFloat)cornerRadius;
返回从左上方绘制的UIBezierPath,因此您的动画从左上角开始.
但是您可以创建自己的UIBezierPath绘制表格中心：
func centerStartBezierPath(frame:CGRect,cornerRadius:CGFloat) -> UIBezierPath {
let path = UIBezierPath()
path.moveToPoint(CGPointMake(frame.width/2.0,0))
path.addLineToPoint(CGPointMake(frame.width-cornerRadius,0))
path.addArcWithCenter(CGPointMake(frame.width-cornerRadius,cornerRadius),radius: cornerRadius,startAngle: CGFloat(-M_PI/2),endAngle: 0,clockwise: true)
path.addLineToPoint(CGPointMake(frame.width,frame.height-cornerRadius))
path.addArcWithCenter(CGPointMake(frame.width-cornerRadius,frame.height-cornerRadius),startAngle: 0,endAngle: CGFloat(M_PI/2),clockwise: true)
path.addLineToPoint(CGPointMake(cornerRadius,frame.height))
path.addArcWithCenter(CGPointMake(cornerRadius,startAngle: CGFloat(M_PI/2),endAngle: CGFloat(M_PI),clockwise: true)
path.addLineToPoint(CGPointMake(0,cornerRadius))
path.addArcWithCenter(CGPointMake(cornerRadius,startAngle: CGFloat(M_PI),endAngle: CGFloat(M_PI*3/2),clockwise: true)
path.closePath()
path.applyTransform(CGAffineTransformMakeTranslation(frame.origin.x,frame.origin.y))
return path;
}
它的工作原理如下：您也可以更改代码,并从任何点开始.
