swift - SKActions 无法识别某些值的变化

Question

我有 3 组 Sprite (EnemyGroups)，这些组按特定顺序排列(每组延迟一秒)。请看代码:

敌人集团:

struct EnemyGroup    {
    var enemies : [Enemy]
    var isVisible : Bool
    var isStatic : Bool

    func setup   ()  {
    if isStatic {
        for enemy in enemies  {
            enemy.sprite.alpha = 1.0
            enemy.sprite.isUserInteractionEnabled = false

        }
        isVisible = true
    }
        }


    mutating func switchEnemiesON   ()  {
    if !isStatic {
    for enemy in enemies  {

        enemy.sprite.alpha = 1.0
        enemy.sprite.physicsBody?.categoryBitMask = enemyCategory
        enemy.sprite.physicsBody?.collisionBitMask = bombCategory

    }
    isVisible = true
    }
}

mutating func switchEnemiesOFF   ()  {
    if !isStatic {
        for enemy in enemies  {
        enemy.sprite.alpha = 0.0
        enemy.sprite.physicsBody?.collisionBitMask = 0
        enemy.sprite.physicsBody?.categoryBitMask = 0
    }

    isVisible = false
    }
}

在游戏场景中:

   func groupActionSequence (enemyGroup: EnemyGroup)  {
    for enemy in enemyGroup.enemies {
    var enemyGroupWithAction = enemyGroup
    let groupSequence = SKAction.sequence([
        SKAction.run({ enemyGroupWithAction.switchEnemiesON() }),
        SKAction.wait(forDuration: showTime),
        SKAction.run({ enemyGroupWithAction.switchEnemiesOFF() }),
        SKAction.wait(forDuration: hideTime)
        ])

    let repeatGroupAction = SKAction.repeatForever(groupSequence)
    enemy.sprite.run(repeatGroupAction)
    }
}

func groupActionSequenceWithDelay (delayTime: TimeInterval, enemyGroup: EnemyGroup, groupKey: String)   {
    for enemy in enemyGroup.enemies {

        var group = enemyGroup
    let groupSequence = SKAction.sequence([
        SKAction.run({ group.setup() }),
        SKAction.wait(forDuration: delayTime),
        SKAction.run({ self.groupActionSequence(enemyGroup: enemyGroup) })
        ])

    enemy.sprite.run(groupSequence, withKey: groupKey)
    }
}

为敌人群体设置行动:

 groupActionSequenceWithDelay(delayTime: 0, enemyGroup: enemyGroup1, groupKey: "group1")
 groupActionSequenceWithDelay(delayTime: 1, enemyGroup: enemyGroup2, groupKey: "group2")
 groupActionSequenceWithDelay(delayTime: 2, enemyGroup: enemyGroup3, groupKey: "group3")

我将 enemyGroup1 和 enemyGroup2 设置为 isStatic = false 并将 enemyGroup3 设置为 isStatic = true 。我将 enemyGroup1 和 enemyGroup2 isStatic 更改为 true 操作仍在 enemyGroup1 上运行> 和 enemyGroup2 就好像isStatic = false。我怎样才能让switchEnemiesOFF()和switchEnemiesON()识别isStatic`值的变化？另外，我不想停止这些 Action ，因为我想保持每个组的相同顺序，它们的运行 Action 有一秒的差异，这就是为什么我用 if 语句来保护一些函数。

Answer 1

使 EnemyGroup 成为类而不是结构。

因为它是一个结构体，在运行 block 闭包中捕获的 enemyGroupWithAction 变量是您在参数中收到的变量的副本(也是作为参数传递给函数的变量的副本)。这些副本中的每一个都有自己独立的值(Struct 是一种值类型)并且单独存在。如果 enemyGroup 是一个对象(类)，则只会捕获引用(类是引用类型)并且对 is 属性的任何修改都会影响原始对象实例。