Ios spritekit未开始接触三个对象未工作

我正在通过三个节点尝试[didBeginContact]。我是用密码写的。 但它不能正常工作。当白色矩形折叠而不点击黑色或白色矩形时， println（“黑色”）和println（“蓝色”）作品。。。 当白色矩形击中黑色矩形时，打印（“蓝色”）工作

导入SpriteKit
类游戏场景：SKScene，SKPhysicContactDelegate{
让blackCategory:UInt32=0x11）根据您的联系人处理程序，您应该将类别设置为

    let whiteCategory:  UInt32 = 0x1 << 0
    let blackCategory:  UInt32 = 0x1 << 1
    let blueCategory:   UInt32 = 0x1 << 2

以上内容应该是

    blueSquare.physicsBody?.categoryBitMask = blueCategory
    blueSquare.physicsBody?.contactTestBitMask = whiteCategory

3） 这里不需要第三个接触体

func didBeginContact(contact: SKPhysicsContact!) {

    var firstBody, secondBody: SKPhysicsBody

    if contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask {
        firstBody = contact.bodyA
        secondBody = contact.bodyB
    } else {
        firstBody = contact.bodyB
        secondBody = contact.bodyA
    }

    if ((firstBody.categoryBitMask & whiteCategory) != 0 &&
        (secondBody.categoryBitMask & blackCategory != 0)) {
            //secondBody.node?.removeFromParent()
            println("black")
    }


    if ((firstBody.categoryBitMask & whiteCategory != 0) &&
        (secondBody.categoryBitMask & blueCategory != 0)) {
            //secondBody.node?.removeFromParent()
            println("blue")
    }
}

“不工作”不是问题描述
    blueSquare.physicsBody?.categoryBitMask = blueCategory
    blueSquare.physicsBody?.contactTestBitMask = whiteCategory

func didBeginContact(contact: SKPhysicsContact!) {

    var firstBody, secondBody: SKPhysicsBody

    if contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask {
        firstBody = contact.bodyA
        secondBody = contact.bodyB
    } else {
        firstBody = contact.bodyB
        secondBody = contact.bodyA
    }

    if ((firstBody.categoryBitMask & whiteCategory) != 0 &&
        (secondBody.categoryBitMask & blackCategory != 0)) {
            //secondBody.node?.removeFromParent()
            println("black")
    }


    if ((firstBody.categoryBitMask & whiteCategory != 0) &&
        (secondBody.categoryBitMask & blueCategory != 0)) {
            //secondBody.node?.removeFromParent()
            println("blue")
    }
}

    whiteRectangle.physicsBody?.contactTestBitMask = blackCategory
    whiteRectangle.physicsBody?.contactTestBitMask = blueCategory