小编典典

按住时如何使Button连续调用函数(SpriteKit)

swift

我正在使用Sprite
Kit制作游戏,并且当您按住向左/向右移动按钮时,我希望角色在屏幕上移动。问题在于他仅在轻按按钮时才移动,而没有保持住。我到处都在寻找解决方案,但似乎无济于事!

这是我的代码;

class Button: SKNode
{
   var defaultButton: SKSpriteNode // defualt state
   var activeButton: SKSpriteNode  // active state

   var timer = Timer()

   var action: () -> Void

   //default constructor
   init(defaultButtonImage: String, activeButtonImage: String, buttonAction: @escaping () -> Void )
   {
      //get the images for both button states
      defaultButton = SKSpriteNode(imageNamed: defaultButtonImage)
      activeButton = SKSpriteNode(imageNamed: activeButtonImage)

      //hide it while not in use
      activeButton.isHidden = true 
      action = buttonAction

      super.init()

      isUserInteractionEnabled = true

      addChild(defaultButton)
      addChild(activeButton)    
   }

   //When user touches button
   override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?)
   {
      action()

      //using timer to repeatedly call action, doesnt seem to work...
      self.timer = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(getter: Button.action), userInfo: nil, repeats: true)

      //swtich the image of our button
      activeButton.isHidden = false
      defaultButton.isHidden = true

   }

   code..........

在我的游戏场景中…

// *** RIGHT MOVEMENT ***
      let rightMovementbutton = Button(defaultButtonImage: "arrow", activeButtonImage: "arrowActive", buttonAction:
      {

         let moveAction = SKAction.moveBy(x: 15, y: 0, duration: 0.1)
         self.player.run(moveAction)


      })

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2020-07-07

共1个答案

小编典典

您知道什么时候触摸了按钮,因为它touchesBegan被调用了。然后,您必须设置一个标志以指示按钮被按下。

override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
    let touch = touches.first!
    if leftButton.containsPoint(touch.locationInNode(self)) {
        leftButtonIsPressed = true
    }
    if rightButton.containsPoint(touch.locationInNode(self)) {
        rightButtonIsPressed = true
    }
}

在中update(),调用标记为true的函数:

update() {
   if leftButtonIsPressed == true {
        moveLeft()
    }

   if rightButtonIsPressed == true {
        moveRight()
    }

}

您可以在touchesEnded调用该按钮时将标志设置为false :

override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
    let touch = touches.first!
    if leftButton.containsPoint(touch.locationInNode(self)) {
        leftButtonIsPressed = false
    }
    if rightButton.containsPoint(touch.locationInNode(self)) {
        rightButtonIsPressed = flase
    }
}

编辑:

正如KoD所指出的那样,一种更干净的方法(用于移动按钮)SKAction可以消除对标志的需要:

  1. 定义SKActionsmoveTo x:0moveTo x:frame.widthdidMoveTo(View:)
  2. 在中touchesBegan,在指定SKAction密钥的正确对象上运行正确的SKAction。
  3. 在中touchesEnded,删除相关的SKAction。

您必须做一些数学运算来计算对象必须移动多少点,然后根据该距离和移动速度(以每秒点数为单位)设置SKAction的持续时间。

或者,(由于KnightOfDragons的帮助)创建了一个SKAction.MoveBy x:以较小的距离(基于您所需的移动速度)并且持续时间为1/60
秒的。SKAction.repeatForever触摸按钮时,请永久重复此操作(),并在释放按钮时删除重复的SKAction。

2020-07-07