如何在 Swift 3.0 中拖放精灵？

Question

我想要做的就是能够在屏幕上拖放一个精灵。我试过以下代码：

override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
}

override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
    for touch in (touches ) {
        let location = touch.locationInNode(self)
        if ball.containsPoint(location) {
            ball.position = location    
}
}
}

此代码确实有效，但是，当我快速拖动球时，我猜它检测到“球”不再包含点“位置”并且球停止了，这意味着我又捡起了球。我希望球能够快速响应我的触球，这样球就不会停止移动。我该怎么做？

Answer 1

这是在 Sprite Kit 中执行此操作的正确方法。就像我在评论中所说的那样，您需要将移动节点分配给激活状态，在这种情况下，我使用一个名为 movableNode 的变量来执行我的激活状态。当您触摸球时，它会通过将其分配给movableNode 来激活。然后当你拖动你的手指时，movableNode 会随着拖动而移动，然后一旦你松开，你通过将movableNode 设置为 nil 进入停用状态。请注意，此代码仅适用于单点触控应用程序，如果您想处理多点触控，则需要跟踪哪个触控在进行拖动。

var movableNode : SKNode?

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first {
        let location = touch.locationInNode(self)
        if ball.containsPoint(location) {
            movableNode = ball
            movableNode!.position = location    
        }
    }
}

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first where movableNode != nil {
        movableNode!.position = touch.locationInNode(self)
    }
}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first where movableNode != nil {
        movableNode!.position = touch.locationInNode(self)
        movableNode = nil
    }
}
override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first {
        movableNode = nil
    }
}

Answer 2

KnightOFDragon 解决方案运行良好。如果您不想将精灵中心位置移动到您的手指触摸屏幕的位置并且您想将精灵从其中心原始位置移动，我只是添加了几行。

var movableNode : SKNode?
var ballStartX: CGFloat = 0.0
var ballStartY: CGFloat = 0.0

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first {
        let location = touch.location(in: self)
        if (map?.contains(location))! {
            movableNode = ball
            ballStartX =  (movableNode?.position.x)! - location.x // Location X of your sprite when touch started
            ballStartY =  (movableNode?.position.y)! - location.y // Location Y of your sprite when touch started
        }
    }
}

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let touch = touches.first, movableNode != nil {
        let location = touch.location(in: self)
        movableNode!.position = CGPoint(x: location.x+ballStartX, y: location.y+ballStartY) // Move node around with distance to your finger
    }
}

override  func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    if let _ = touches.first, movableNode != nil {
        movableNode = nil
    }
}
 override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first {
    movableNode = nil
}

Answer 3

我有一个实现，其中我对 UIImageView 进行了子类化并将其称为“DraggableImage”

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        originalPosition = self.center
    }

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        if let touch = touches.first {
            let position = touch.location(in: self.superview)
            self.center = CGPoint(x: position.x, y: position.y)
        }
    }

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {

        self.center = originalPosition
    }