Question

大家好我正在制作一个sprite-kit应用程序，用户必须能够绘制多行。为此，我制作了以下代码。

import SpriteKit

class GameScene: SKScene {

    var line = SKShapeNode()
    var path = CGPathCreateMutable()
    var touch: UITouch!
    var location:CGPoint!

    override func didMoveToView(view: SKView) {

    }

    override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
        /* Called when a touch begins */
        touch = touches.anyObject() as UITouch!
        location = touch.locationInNode(self)

        drawLine()
    }

    override func touchesEnded(touches: NSSet!, withEvent event: UIEvent!) {
        self.delete(line)
    }

    func drawLine() {

        CGPathMoveToPoint(path, nil, location.x, location.y)
        CGPathAddLineToPoint(path, nil, 500.0, 500.0)

        line.path = path
        line.strokeColor = UIColor.redColor()
        line.lineWidth = 5.0
        self.addChild(line)

    }

    override func update(currentTime: CFTimeInterval) {
        /* Called before each frame is rendered */
    }
}

这样可行，但当用户尝试绘制第二行时，应用程序崩溃。有人可以向我解释为什么会这样吗？

------ ------编辑

我想我需要使用一系列行，所以我做了类似的事情：

var line: [[SKShapeNode]] = []

这给了我以下错误： [[SKShapeNode]]没有名为'path'的成员。所以我虽然我必须使路径变量也是一个数组，但这只给了我第二个错误：GameScene没有名为'path'的成员。所以我把它全部改回来但我仍然认为我必须使用数组，尽管我无法弄清楚如何让它工作。

Answer 1

复制并粘贴此..现在，您每次都会重新定义您的行

  import SpriteKit

    class GameScene: SKScene {

        var line = SKShapeNode()
        var path = CGPathCreateMutable()
        var touch: UITouch!
        var location:CGPoint!

        override func didMoveToView(view: SKView) {

        }

        override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
            /* Called when a touch begins */
            touch = touches.anyObject() as UITouch!
            location = touch.locationInNode(self)

            drawLine()
        }

        override func touchesEnded(touches: NSSet!, withEvent event: UIEvent!) {
            self.delete(line)
        }

        func drawLine() {

            CGPathMoveToPoint(path, nil, location.x, location.y)
            CGPathAddLineToPoint(path, nil, 500.0, 500.0)

            SKShapeNode *line = [SKShapeNode node]; //redfine line every time 
            line.path = path
            line.strokeColor = UIColor.redColor()
            line.lineWidth = 5.0
            self.addChild(line)

        }

        override func update(currentTime: CFTimeInterval) {
            /* Called before each frame is rendered */
        }
    }

xcode 6绘制线错误

1 个答案: