我的精灵位置有一个奇怪的问题，我试过干净的构建，重新启动xcode，并运行不同的方案（iPhone5s，iPhone6），它们都返回同样的奇怪问题。 我试图通过以下方式设置精灵的位置：
balls.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame) + self.frame.size.width)
所以当我将println（balls.position）打印到控制台时，它返回（0.0,0.0）
但是当我尝试
时println(CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame) + self.frame.size.width)
它返回（512.0,1408.0），这是球的正确位置。
我遇到了最后一个函数func ballPosition的问题，它用于确定精灵“球”的位置。由于某种原因它总是（0,0）。< / p>
以下是我的测试项目的完整代码：
import SpriteKit
class GameScene: SKScene, SKPhysicsContactDelegate {
var circle = SKShapeNode()
var balls = SKShapeNode()
var ballColor = ["red", "blue", "green", "yellow"]
var points = ["up", "down", "left", "right"]
override func didMoveToView(view: SKView) {
backgroundColor = SKColor.whiteColor()
// set circle position and size
circle = SKShapeNode(circleOfRadius: 100 ) // Size of Circle
circle.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame)) //Middle of Screen
circle.strokeColor = SKColor.whiteColor()
circle.fillColor = SKColor.orangeColor()
self.addChild(circle)
}
override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
/* Called when a touch begins */
circleRotate()
ballPosition()
// test ball position, this is the part with the issue I mentioned above.
println(balls.position) // (0, 0)
println(CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame) + self.frame.size.width)) // (512.0,1408.0)
}
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
}
func circleRotate() {
let circleAction = SKAction.rotateByAngle(CGFloat(-M_PI * 2 / 3), duration: 0.1)
circle.runAction(SKAction.repeatAction(circleAction, count: 1))
}
func ballMove() {
let ballMovement = SKAction.moveTo(CGPoint(x: CGRectGetMidX(self.frame), y: CGRectGetMidY(self.frame)), duration: 5)
balls.runAction(ballMovement)
}
func randomColor() {
let ballColorIndex = Int(arc4random_uniform(UInt32(ballColor.count)))
balls = SKShapeNode(circleOfRadius: 10 )
if ballColorIndex == 0 {
balls.strokeColor = SKColor.whiteColor()
balls.fillColor = SKColor.redColor()
// balls.zPosition = 10
ballMove()
} else if ballColorIndex == 1 {
balls.strokeColor = SKColor.whiteColor()
balls.fillColor = SKColor.blueColor()
// balls.zPosition = 10
ballMove()
} else if ballColorIndex == 2 {
balls.strokeColor = SKColor.whiteColor()
balls.fillColor = SKColor.greenColor()
// balls.zPosition = 10
ballMove()
} else if ballColorIndex == 3 {
balls.strokeColor = SKColor.whiteColor()
balls.fillColor = SKColor.yellowColor()
// balls.zPosition = 10
ballMove()
}
}
func ballPosition() {
let ballPointIndex = Int(arc4random_uniform(UInt32(points.count)))
if ballPointIndex == 0 {
balls.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame) + self.frame.size.width)
randomColor()
self.addChild(balls)
} else if ballPointIndex == 1 {
balls.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame) - self.frame.size.height)
randomColor()
self.addChild(balls)
} else if ballPointIndex == 2 {
balls.position = CGPoint(x:CGRectGetMidX(self.frame) - self.frame.size.width, y:CGRectGetMidY(self.frame))
randomColor()
self.addChild(balls)
} else if ballPointIndex == 3 {
balls.position = CGPoint(x:CGRectGetMidX(self.frame) + self.frame.size.width, y:CGRectGetMidY(self.frame))
randomColor()
self.addChild(balls)
}
}
}
答案 0 :(得分：0)
问题是您在randomColor()中覆盖了球 - 您正在创建一个尚未添加到父视图中的新节点。
潜在的问题是您以一种导致混淆和错误的方式构建代码。你应该保持你的功能单一用途。他们应该做他们所说的。一个名为randomColor（）的函数不应移动球移动或设置球的大小。位置功能不应设置颜色。
我重新安排了代码然后运行它。那个错误是固定的。你可以看到我改变了什么，现在应该能够进一步发展。祝你好运。
import SpriteKit
class GameScene: SKScene, SKPhysicsContactDelegate {
var circle = SKShapeNode()
var ball = SKShapeNode(circleOfRadius: 10)
var ballColor = ["red", "blue", "green", "yellow"]
var points = ["up", "dowm", "left", "right"]
override func didMoveToView(view: SKView) {
backgroundColor = SKColor.whiteColor()
circle = SKShapeNode(circleOfRadius: 100 ) // Size of Circle
circle.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame)) //Middle of Screen
circle.strokeColor = SKColor.whiteColor()
circle.fillColor = SKColor.orangeColor()
self.addChild(circle)
self.addChild(ball)
ball.position = CGPointMake(150, 0)
println("Initial Ball Pos: \(ball.position)")
}
override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
circleRotate()
setRandomBallPosition()
setRandomColor()
ballMove()
// test ball position
println("--------------")
println("Ball Pos: \(ball.position)")
println("Circle pos: \(circle.position)")
println("Midpoint: \(CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame) + self.frame.size.width))")
println("--------------")
}
override func update(currentTime: CFTimeInterval) {
/* Called before each frame is rendered */
}
func circleRotate() {
let circleAction = SKAction.rotateByAngle(CGFloat(-M_PI * 2 / 3), duration: 0.1)
circle.runAction(SKAction.repeatAction(circleAction, count: 1))
}
func ballMove() {
let ballMovement = SKAction.moveTo(CGPoint(x: CGRectGetMidX(self.frame), y: CGRectGetMidY(self.frame)), duration: 5)
ball.runAction(ballMovement)
}
func setRandomColor() {
ball.strokeColor = SKColor.whiteColor()
let ballColorIndex = Int(arc4random_uniform(UInt32(ballColor.count)))
switch(ballColorIndex) {
case 0:
ball.fillColor = SKColor.redColor()
case 1:
ball.fillColor = SKColor.blueColor()
case 2:
ball.fillColor = SKColor.greenColor()
case 3:
ball.fillColor = SKColor.yellowColor()
default:
println("Unexpected random index value ", ballColorIndex)
}
}
func setRandomBallPosition() {
let ballPointIndex = Int(arc4random_uniform(UInt32(points.count)))
println("ballPointIndex = \(ballPointIndex)")
switch(ballPointIndex) {
case 0:
ball.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame) + (self.frame.size.width / 2))
case 1:
ball.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame) - (self.frame.size.height / 2))
case 2:
ball.position = CGPoint(x:CGRectGetMidX(self.frame) - (self.frame.size.width / 2), y:CGRectGetMidY(self.frame))
case 3:
ball.position = CGPoint(x:CGRectGetMidX(self.frame) + (self.frame.size.width / 2), y:CGRectGetMidY(self.frame))
default:
println("Unexpected random index value: ", ballPointIndex)
}
println("ball position = \(ball.position)")
}
}