当在 Swift Spritekit 中触摸并按住屏幕时，我将如何向上移动我的节点？

Question

当用户触摸屏幕并按住它时，我希望SKSpriteNode 飞起来，当用户停止触摸后，它又会掉到地上。现在我正在使用敲击将节点向上移动并在 touchesEnded 中将重力设置为 false 以使其落到地上。我将如何让它发挥作用。谢谢！

   var touchingScreen = false

    override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
    super.touchesBegan(touches, withEvent: event)
    touchingScreen = true
}


    override func touchesCancelled(touches: Set<NSObject>!, withEvent event: UIEvent!) {
    super.touchesCancelled(touches, withEvent: event)
    touchingScreen = false
}

override func touchesEnded(touches: Set<NSObject>, withEvent event: UIEvent) {
    super.touchesEnded(touches, withEvent: event)
    touchingScreen = false
}

 override func update(currentTime: CFTimeInterval) {
    if touchingScreen {
        // Adjust the CGVector to suit your needs.
        heroNode.physicsBody!.applyImpulse(CGVector(dx: 0, dy: 10))


    }
}

Answer 1

首先，您需要跟踪用户何时触摸并按住屏幕。你可以这样做，在你的SKScene:

var touchingScreen = false

override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
    super.touchesBegan(touches, withEvent: event)
    touchingScreen = true
}

override func touchesCancelled(touches: Set<NSObject>!, withEvent event: UIEvent!) {
    super.touchesCancelled(touches, withEvent: event)
    touchingScreen = false
}

override func touchesEnded(touches: Set<NSObject>, withEvent event: UIEvent) {
    super.touchesEnded(touches, withEvent: event)
    touchingScreen = false
}

其次，您现在需要在用户按下屏幕时让对象向上移动，再次在您的SKScene 中：

override func update(currentTime: CFTimeInterval) {
    if touchingScreen {
        // Adjust the CGVector to suit your needs.
        sprite.physicsBody!.applyImpulse(CGVector(dx: 0, dy: 50))
    }
}

或者，如果您希望对象以恒定速度向上移动，请替换：

sprite.physicsBody!.applyImpulse(CGVector(dx: 0, dy: 50))

与

sprite.physicsBody!.velocity = CGVector(dx: yourDx, dy: yourDy)

希望有帮助！