字符移动代码不工作- Unity3D单元脚本

Question

我有一个脚本，移动字符的方向取决于它与什么碰撞。下面是我的代码：

var speed : float = 1;
private var leftBool : boolean;
private var rightBool : boolean;
private var upBool : boolean;
private var downBool : boolean;

function Update () {
    if(leftBool == true) {
        gameObject.GetComponent(Rigidbody2D).velocity.x =         gameObject.GetComponent(Rigidbody2D).velocity.x - speed * Time.deltaTime;
        rightBool = false;
        upBool = false;
        downBool = false;
    }
    if(upBool == true) {
        gameObject.GetComponent(Rigidbody2D).velocity.y = gameObject.GetComponent(Rigidbody2D).velocity.y + speed * Time.deltaTime;
        rightBool = false;
        leftBool = false;
        downBool = false;
    }
    if(rightBool == true) {
        gameObject.GetComponent(Rigidbody2D).velocity.x = gameObject.GetComponent(Rigidbody2D).velocity.x + speed * Time.deltaTime;
        rightBool = false;
        leftBool = false;
        downBool = false;
    }
    if(downBool == true) {
        gameObject.GetComponent(Rigidbody2D).velocity.y = gameObject.GetComponent(Rigidbody2D).velocity.y - speed * Time.deltaTime;
        rightBool = false;
        leftBool = false;
        upBool = false;
    }   
}

function Start () {
    leftBool = true;
}


function OnTriggerEnter2D (other : Collider2D) {
    if(other.GetComponent(Arrows).rotationNumber == 1) {
        leftBool = true;
        Debug.Log("Entered");
    }
    if(other.GetComponent(Arrows).rotationNumber == 2) {
        upBool = true;
        Debug.Log("Entered");
    }
    if(other.GetComponent(Arrows).rotationNumber == 3) {
        rightBool = true;
        Debug.Log("Entered");
    }
    if(other.GetComponent(Arrows).rotationNumber == 4) {
        downBool = true;
        Debug.Log("Entered");
    }
}

这一切为什么要发生？谢谢。

Answer 1

起初，当假设与rotationNumber==1发生冲突时，leftBool仍然为真。根据声明和Update()中的代码，其他代码为false。现在，当您与rotationNumber==2发生冲突时，upBool将返回true。但如前所述，在Update()中，leftBool仍然为true，并且它位于代码执行顺序的顶部，upBool将立即返回false。所以，你永远不会得到if(upBool == true){}个东西(顺便说一句，你不必使用==操作符来表示布尔，if(upBool)表示true，if(!upBool)表示false)。希望它能澄清你的困惑。现在，有很多方法可以实现你想要的。但是，我修改了你的代码，这样你就能明白发生了什么-

var speed : float = 1;
private var leftBool : boolean;
private var rightBool : boolean;
private var upBool : boolean;
private var downBool : boolean;

function Start () {
    leftBool = true;
}

function Update () {
    if(leftBool) {
        gameObject.GetComponent(Rigidbody2D).velocity.x = gameObject.GetComponent(Rigidbody2D).velocity.x - speed * Time.deltaTime; 
    }
    if(upBool) {
        gameObject.GetComponent(Rigidbody2D).velocity.y = gameObject.GetComponent(Rigidbody2D).velocity.y + speed * Time.deltaTime;   
    }
    if(rightBool) {
        gameObject.GetComponent(Rigidbody2D).velocity.x = gameObject.GetComponent(Rigidbody2D).velocity.x + speed * Time.deltaTime;
    }
    if(downBool) {
        gameObject.GetComponent(Rigidbody2D).velocity.y = gameObject.GetComponent(Rigidbody2D).velocity.y - speed * Time.deltaTime;
    }   
}

function OnTriggerEnter2D (other : Collider2D) {
    if(other.GetComponent(Arrows).rotationNumber == 1) {
        leftBool = true;
        rightBool = false;
        upBool = false;
        downBool = false;
        Debug.Log("Entered");
    }
    if(other.GetComponent(Arrows).rotationNumber == 2) {
        upBool = true;
        rightBool = false;
        leftBool = false;
        downBool = false;
        Debug.Log("Entered");
    }
    if(other.GetComponent(Arrows).rotationNumber == 3) {
        rightBool = true;
        upBool = false;
        leftBool = false;
        downBool = false;
        Debug.Log("Entered");
    }
    if(other.GetComponent(Arrows).rotationNumber == 4) {
        downBool = true;
        rightBool = false;
        leftBool = false;
        upBool = false;
        Debug.Log("Entered");
    }
}

希望这能有所帮助。