如何从自定义SKAction Swift中引用节点

我可以按如下方式创建自定义操作：

extension SKAction {
  class func move(from: CGPoint, halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

extension SKNode {
  func move(halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let from = self.position
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

//Setup
let node = SKNode()
node.position = CGPoint(x: 50, y: 50)
let destination = CGPoint(x: 100, y: 100)

//Move from node's current position half way towards the destination
let action2 = node.move(halfWayTo: destination, duration: 1)
node.run(action2)

然后我用这个：

//Setup
let node = SKNode()
node.position = CGPoint(x: 50, y: 50)
let destination = CGPoint(x: 100, y: 100)

//Move from node's current position half way towards the destination
let action = SKAction.move(from: node.position, halfWayTo: destination, duration: 1)
node.run(action)

但按照标准：

SKAction.move(to: destination, duration: 1)

我宁愿说：

let action = SKAction.move(halfWayTo: destination, duration: 1)
node.run(action)

---

但我不知道如何从自定义SKAction中引用“节点”，以便获得它的位置并计算中间点？

您使用

self

extension SKAction {
  class func move(halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let from = self.position
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

然后打电话（如你所说）

---

您可以使用

self

extension SKAction {
  class func move(halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let from = self.position
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

然后打电话（如你所说）

---

我仍然不确定SKAction是否有对它所应用的节点的引用——即使它正在运行——或者即使有，我也不确定是否有办法访问它。如果有人知道，请告诉我

我想到了如下一种方法：

extension SKAction {
  class func move(from: CGPoint, halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

extension SKNode {
  func move(halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let from = self.position
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

//Setup
let node = SKNode()
node.position = CGPoint(x: 50, y: 50)
let destination = CGPoint(x: 100, y: 100)

//Move from node's current position half way towards the destination
let action2 = node.move(halfWayTo: destination, duration: 1)
node.run(action2)

扩展SKNode而不是扩展SKAction，如下所示：

extension SKAction {
  class func move(from: CGPoint, halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

extension SKNode {
  func move(halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let from = self.position
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

//Setup
let node = SKNode()
node.position = CGPoint(x: 50, y: 50)
let destination = CGPoint(x: 100, y: 100)

//Move from node's current position half way towards the destination
let action2 = node.move(halfWayTo: destination, duration: 1)
node.run(action2)

然后按如下方式使用：

extension SKAction {
  class func move(from: CGPoint, halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

extension SKNode {
  func move(halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let from = self.position
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

//Setup
let node = SKNode()
node.position = CGPoint(x: 50, y: 50)
let destination = CGPoint(x: 100, y: 100)

//Move from node's current position half way towards the destination
let action2 = node.move(halfWayTo: destination, duration: 1)
node.run(action2)

---

我仍然不确定SKAction是否有对它所应用的节点的引用——即使它正在运行——或者即使有，我也不确定是否有办法访问它。如果有人知道，请告诉我

我想到了如下一种方法：

extension SKAction {
  class func move(from: CGPoint, halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

extension SKNode {
  func move(halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let from = self.position
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

//Setup
let node = SKNode()
node.position = CGPoint(x: 50, y: 50)
let destination = CGPoint(x: 100, y: 100)

//Move from node's current position half way towards the destination
let action2 = node.move(halfWayTo: destination, duration: 1)
node.run(action2)

扩展SKNode而不是扩展SKAction，如下所示：

extension SKAction {
  class func move(from: CGPoint, halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

extension SKNode {
  func move(halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let from = self.position
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

//Setup
let node = SKNode()
node.position = CGPoint(x: 50, y: 50)
let destination = CGPoint(x: 100, y: 100)

//Move from node's current position half way towards the destination
let action2 = node.move(halfWayTo: destination, duration: 1)
node.run(action2)

然后按如下方式使用：

extension SKAction {
  class func move(from: CGPoint, halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

extension SKNode {
  func move(halfWayTo: CGPoint, duration: TimeInterval) -> SKAction {
    let from = self.position
    let midPoint = CGPoint(x: (from.x + halfWayTo.x)/2, y: (from.y + halfWayTo.y)/2 )
    return SKAction.move(to: midPoint, duration: duration)
  }
}

//Setup
let node = SKNode()
node.position = CGPoint(x: 50, y: 50)
let destination = CGPoint(x: 100, y: 100)

//Move from node's current position half way towards the destination
let action2 = node.move(halfWayTo: destination, duration: 1)
node.run(action2)

---

非常感谢ValyreanGroup。我现在已经尝试了你的建议。我在“let from=self.position”行中得到一个编译错误，它说：“类型‘SKAction’没有成员‘position’，我意识到我原来的问题中有语法错误，这意味着可以执行node.move，但这是错误的。它需要是SKAction.move，所以我编辑了我的原始问题。正如@Adahus所指出的，SKAction没有

职位

成员。非常感谢ValyreanGroup。我现在已经尝试了你的建议。我在“let from=self.position”行中得到一个编译错误，它说：“类型‘SKAction’没有成员‘position’，我意识到我原来的问题中有语法错误，这意味着可以执行node.move，但这是错误的。它需要是SKAction.move，所以我编辑了我的原始问题。正如@Adahus所指出的，SKAction没有

位置

成员。我一直在尝试做类似的事情，我想不出任何方法来做。正如您所意识到的，当您调用

SKAction.move（中途转到：）

时，

SKAction

无法访问相关的

SKNode

。您对

SKNode

的扩展是一个有趣的想法，但我认为我将继续使用对

SKAction

的扩展，并只传递起点，就像您在原始示例中所做的那样。似乎最好在代码中明确说明我们正在创建一个

SKAction

。我同意作为SKAction的扩展更好。我一直在尝试做类似的事情，但我想不出任何方法。正如您所意识到的，当您调用

SKAction.move（中途转到：）

时，

SKAction

无法访问相关的

SKNode

。您对

SKNode

的扩展是一个有趣的想法，但我认为我将继续使用对

SKAction

的扩展，并只传递起点，就像您在原始示例中所做的那样。似乎最好在代码中明确说明我们正在创建一个

SKAction

。我同意作为SKAction的扩展更好。