Swift 如何用两种不同的颜色画一个空心圆？

我非常熟悉绘制填充的createEllipseInRect形状节点，但我想知道是否有一种方法可以通过编程实现这一点。我想要一个圆心，两边各有两种颜色。我没有代码，因为我不知道从哪里开始

---

非常感谢你的帮助

您可以尝试使用SKCropNode，这样可以只显示每个圆的一半。请参见下面的代码以获取此示例

class GameScene: SKScene {
override func didMoveToView(view: SKView) {

    anchorPoint = CGPointMake(0.5, 0.5)

    // Half Circle #1

    let myCrop1 = SKCropNode()

    let myMask1 = SKSpriteNode(color: UIColor.blackColor(), size: CGSizeMake(100, 100))
    myMask1.position.y = -50

    let circle1 = SKShapeNode(circleOfRadius: 50)
    circle1.lineWidth = 0
    circle1.fillColor = UIColor.blueColor()

    myCrop1.addChild(circle1)
    myCrop1.maskNode = myMask1
    addChild(myCrop1)

    // Half Circle #2

    let myCrop2 = SKCropNode()

    let myMask2 = SKSpriteNode(color: UIColor.blackColor(), size: CGSizeMake(100, 100))
    myMask2.position.y = 50

    let circle2 = SKShapeNode(circleOfRadius: 50)
    circle2.lineWidth = 0
    circle2.fillColor = UIColor.redColor()

    myCrop2.addChild(circle2)
    myCrop2.maskNode = myMask2
    addChild(myCrop2)


    }

}

我以前很少使用SKCropNode，所以我不确定我的代码有多好，但下面是我在iPhone上得到的结果

编辑：如果需要，您应该能够添加第三个SKCropNode以使圆心透明

编辑：下面是透明中心

class GameScene: SKScene {
override func didMoveToView(view: SKView) {

    anchorPoint = CGPointMake(0.5, 0.5)

    let transparentCenterMask = SKShapeNode(circleOfRadius: 50)
    transparentCenterMask.lineWidth = 20
    let transparentCenterCrop = SKCropNode()
    transparentCenterCrop.maskNode = transparentCenterMask

    // Half Circle #1

    let myCrop1 = SKCropNode()

    let myMask1 = SKSpriteNode(color: UIColor.blackColor(), size: CGSizeMake(100, 100))
    myMask1.position.y = -50

    let circle1 = SKShapeNode(circleOfRadius: 50)
    circle1.lineWidth = 0
    circle1.fillColor = UIColor.blueColor()

    myCrop1.addChild(circle1)
    myCrop1.maskNode = myMask1
    transparentCenterCrop.addChild(myCrop1)

    // Half Circle #2

    let myCrop2 = SKCropNode()

    let myMask2 = SKSpriteNode(color: UIColor.blackColor(), size: CGSizeMake(100, 100))
    myMask2.position.y = 50

    let circle2 = SKShapeNode(circleOfRadius: 50)
    circle2.lineWidth = 0
    circle2.fillColor = UIColor.redColor()

    myCrop2.addChild(circle2)
    myCrop2.maskNode = myMask2
    transparentCenterCrop.addChild(myCrop2)

    addChild(transparentCenterCrop)


    }

}

---

好的，你能告诉我从哪里开始吗？这正是我想要的！非常感谢你！