Question

使用UIBezierPath给view切圆角，为什么只对一边有效

Answer 1

override func drawRect(rect: CGRect) {
//切左上右上圆角
let maskPath = UIBezierPath(roundedRect:self.bounds, byRoundingCorners: [.TopLeft,.TopRight], cornerRadii: CGSizeMake(5.0, 5.0))
let maskLayer = CAShapeLayer()
maskLayer.frame = self.bounds
maskLayer.path = maskPath.CGPath
self.layer.mask = maskLayer

//添加border
let borderLayer = CAShapeLayer()
borderLayer.frame = self.bounds
borderLayer.path = maskPath.CGPath
borderLayer.lineWidth = 0.5
borderLayer.strokeColor = UIColor.lightGrayColor().CGColor
borderLayer.fillColor = UIColor.clearColor().CGColor

let layers:NSArray = self.layer.sublayers! as NSArray

if ((layers.lastObject!.isKindOfClass(CAShapeLayer))) {
layers.lastObject?.removeFromSuperlayer()
}
self.layer.addSublayer(borderLayer)

}