前言

使用 Swift 實現的轉盤菜單，主要用到UIBezierPath、CALayer遮罩繪制扇形UIView，CATransform3DMakeRotation實現旋轉動畫。代碼設計使用默認configureCallback回調方便創建和設置基本屬性，參考UITableView代理和數據源模式，支持AutoLayout和Frame。

效果圖

1.遮罩繪制扇形View

計算扇形曲線位置，通過CALayer的mask屬性繪制出扇形UIView 核心代碼

func setMaskLayer(_ startAngle: CGFloat, endAngle: CGFloat) {
? ? let center = CGPoint(x: bounds.width * 0.5, y: bounds.height * 0.5)
? ? let layer = CAShapeLayer()
? ? path.addArc(withCenter: center, radius: bounds.width * 0.5, startAngle: startAngle, endAngle: endAngle, clockwise: true)
? ? path.addLine(to: center)
? ? layer.path = path.cgPath
? ? layer.rasterizationScale = UIScreen.main.scale
? ? layer.shouldRasterize = true
? ? self.layer.mask = layer
}

2.中間鏤空

func createHole(in view : UIView, radius: CGFloat) ? {
? ? let path = CGMutablePath()
? ? path.addArc(center: view.center, radius: radius, startAngle: 0.0, endAngle: 2.0 * .pi, clockwise: true)
? ? path.addRect(CGRect(origin: .zero, size: view.bounds.size))
? ? let maskLayer = CAShapeLayer()
? ? maskLayer.path = path
? ? maskLayer.fillRule = .evenOdd
? ? view.layer.mask = maskLayer
? ? view.clipsToBounds = true
}

3.旋轉動畫

添加UIPanGestureRecognizer、UITapGestureRecognizer手勢，根據手勢位置使用atan2函數計算旋轉角度，然后用CATransform3DMakeRotation圍繞Z軸旋轉做動畫 核心代碼

func handlePanGesture(_ sender: UIPanGestureRecognizer) {
? ? let location = sender.location(in: self)
? ? switch sender.state {
? ? case .began:
? ? ? ? startPoint = location
? ? case .changed:
? ? ? ? let radian1 = -atan2(startPoint.x - menuLayerView.center.x, startPoint.y - menuLayerView.center.y)
? ? ? ? let radian2 = -atan2(location.x - menuLayerView.center.x, location.y - menuLayerView.center.y)
? ? ? ? menuLayerView.transform = menuLayerView.transform.rotated(by: radian2 - radian1)
? ? ? ? startPoint = location
? ? default:
? ? ? ? let angle = 2 * CGFloat(Double.pi) / CGFloat(cells.count)
? ? ? ? var menuViewAngle = atan2(menuLayerView.transform.b, menuLayerView.transform.a)
? ? ? ? if menuViewAngle < 0 {
? ? ? ? ? ? menuViewAngle += CGFloat(2 * Double.pi)
? ? ? ? }
? ? ? ? var index = cells.count - Int((menuViewAngle + CGFloat(Double.pi / 4)) / angle)
? ? ? ? if index == cells.count {
? ? ? ? ? ? index = 0
? ? ? ? }
? ? ? ? setSelectedIndex(index, animated: true)
? ? }
}
func handleTapGesture(_ sender: UITapGestureRecognizer) {
? ? let location = sender.location(in: menuLayerView)
? ? for (index, cell) in cells.enumerated() {
? ? ? ? if cell.path.contains(location) {
? ? ? ? ? ? setSelectedIndex(index, animated: true)
? ? ? ? }
? ? }
}

4.彈出收起動畫

func openMenuView(withAnimate animate: Bool = true) {
? ? openMenu = true
? ? UIView.animate(withDuration: animate ? configure.animationDuration : 0, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 5.0, options: .curveEaseInOut) {
? ? ? ? self.centerButton.transform = CGAffineTransform(rotationAngle: .pi * -0.5)
? ? ? ? self.centerButton.setImage(self.configure.closeImage, for: .normal)
? ? ? ? self.menuLayerView.transform = CGAffineTransform(scaleX: 1, y: 1).rotated(by: self.currentAngle)
? ? }
}
func closeMenuView(withAnimate animate: Bool = true) {
? ? openMenu = false
? ? let scale = (configure.centerRadius * 2) / bounds.width
? ? UIView.animate(withDuration: animate ? configure.animationDuration : 0, delay: 0, usingSpringWithDamping: 0.7, initialSpringVelocity: 5.0, options: .curveEaseInOut) {
? ? ? ? self.centerButton.transform = .identity
? ? ? ? self.centerButton.setImage(self.configure.openImage, for: .normal)
? ? ? ? self.menuLayerView.transform = CGAffineTransform(scaleX: scale, y: scale).rotated(by: self.currentAngle)
? ? }
}

5.內部細節

考慮到方便布局和使用，內部使用UIView疊加旋轉實現，這里也可以采用Layer直接繪制實現，相對UIView，層次結構會簡單很多

總結

核心代碼已經貼出，完整代碼請查看----->>>CLDemo，如果對你有所幫助，歡迎Star。