我可能错了,但我相信您的手指正在离开节点限制并进入后台。我会这样设置:
// First make the shape available throughout the code and make sure you have a place to save the touch event for later use.
var circle: SKShapeNode!
var circleTouch: UITouch?
// Create the Shape
override func didMoveToView(view: SKView) {
circle = SKShapeNode(circleOfRadius: 30.0)
circle.position = CGPointMake(100, 200)
addChild(circle)
}
// When a finger is placed on the screen, check if it's in the circle, if it is, keep that touch even in memory so we can reference it later because other fingers could touch other things in the scene.
override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
for touch in touches {
if nodeAtPoint(touch.locationInNode(self)) == circle {
circleTouch = touch as? UITouch
}
}
}
// Check if the touch event that is moving is the one that anchored the circle to our finger, if yes, move the circle to the position of the finger.
override func touchesMoved(touches: NSSet, withEvent event: UIEvent) {
for touch in touches {
if circleTouch != nil {
if touch as UITouch == circleTouch! {
let location = touch.locationInNode(self)
circle.position = location
}
}
}
}
// Clean up the touch event when the finger anchoring the circle is raised from the screen.
override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {
for touch in touches {
if circleTouch != nil {
if touch as UITouch == circleTouch! {
circleTouch = nil
}
}
}
}
您也可以在其中使用if let
语句,但nil
为了清楚起见,我进行了检查。