我认为自然的事情是围绕一种个体的主动接触进行组织。在touchesMoved，，touchesEnded和中touchesCancelled，当没有活动触摸时，将忽略所有内容，并忽略不是活动触摸的所有触摸。在中touchesBegan，如果已经有活动的触摸，请忽略新的触摸。最后，在中touchesBegan，如果没有活动的触摸并且该触摸在一个球上，则该触摸变为活动的触摸，并且该球成为被移动的球。草图：
// activeTouch is a UITouch?
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
if activeTouch == nil {
// Look for a touched ball; if found set that as the moving ball
// and set this touch as activeTouch
}
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?){
guard let active = activeTouch else { return }
for touch in touches {
if touch == active {
// Do stuff with the moving ball
}
}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?){
guard let active = activeTouch else { return }
for touch in touches {
if touch == active {
// The moving ball stops moving, reset activeTouch to nil
}
}
}
// Probably touchesCancelled should be the same as touchesEnded, or
// maybe you'd want to move the ball back to the starting position;
// depends on your game.
我以为是那样的。多亏了您的简化模板，我才发现自己在搞乱。谢谢