Question

首先，这是我的第一篇文章，欢迎这个社区的每个人。我已经找到了大量的信息，帮助我解决了迄今为止遇到的问题。现在我遇到了一个我无法解决的问题。我正在做一个“庞”类型的游戏，可能你们中的一些人已经看过或玩过某种变化。所以说到这一点。我目前正试图制作一个与一个类相关联的对象，在舞台上反弹。我决定尝试使用easeIn和easeOut补间。

我声明主文档类中的补间：

public static var upTween:Tween;
    public static var downTween:Tween;

并使用for循环将其值分配给数组的所有对象：

public function bounce(event:Event):void
    {
        for (var i:uint = 0; i < bubbles1.length; i++)
        {
            upTween = new Tween(bubbles1[i], "y", Strong.easeOut, bubbles1[i].y, 250, 2, true);
            downTween = new Tween(bubbles1[i], "y", Strong.easeIn, bubbles1[i].y, stage.stageHeight - 50 - bubbles1[i].height, 2, true);
        }
    }

现在，当我尝试从Bubble.as类中启动补间时，我得到一个空对象引用。

或许更多信息会有所帮助。我正在主类中的公共函数中实例化对象，如下所示：

public function makeBubble(size:Number, xCoordinate:Number, yCoordinate:Number, xDir:Number):void
        {
            if (size == 1)
            {
            bubble = new Bubble(stage);
            bubble.x = xCoordinate;
            bubble.y = yCoordinate;
            bubble.xDirection = xDir;
            bubbles1.push(bubble);
            stage.addChild(bubble);

            }

这是完整的Bubble.as类：

package com.zdravko.pong
{
import flash.display.MovieClip;
import flash.display.Stage;
import flash.events.Event;



public class Bubble extends MovieClip
{
    private var stageRef:Stage;

    var xDirection:Number;
    var yDirection:Number;

    var bubble2:Bubble2;




    public function Bubble(stageRef:Stage) 
    {
        // constructor code
        this.stageRef = stageRef;


        addEventListener(Event.ENTER_FRAME, loop, false, 0, true);

    }

    function loop(event:Event):void
    {
        if(this.x >= stage.stageWidth - this.width)
        {
            this.x = stage.stageWidth - this.width - 5;
            xDirection *= -1;
        }
        if(this.x <= 0)
        {
            this.x = 5;
            xDirection *= -1;
        }
        if(this.y >= stage.stageHeight - 50 - this.height)
        {               
            this.y = stage.stageHeight - 50 - this.height;
            Engine.upTween.start();
        }
        if(this.y <= 250)
        {
            this.y = 250;
            Engine.downTween.start();

        }

        this.x += xDirection;


        if(hitTestObject(Engine.player) && Player.invul == false)
           {
               decreaseEnergy(.4);
               Player.invul = true;
               Player.invulTimer.start();
           }
    }

    public function decreaseEnergy(dmg:Number):void
    {
        Engine.energy.scaleX -= dmg;
    }

    public function takeHit() : void
    {

        makeBubble(2, this.x + 50, this.y + 30, 8, 8);
        makeBubble(2, this.x - 20, this.y - 30, -8, 8);
        removeSelf();
        Engine.playerScore += 500;
        Engine.score.scoreBox.text = Engine.playerScore;
    }

    private function removeSelf() : void
    {
        removeEventListener(Event.ENTER_FRAME, loop);

        if (stageRef.contains(this))
        {
            stageRef.removeChild(this);
        }
    }

    private function makeBubble(size:Number, xCoordinate:Number, yCoordinate:Number, xDir:Number, yDir:Number):void
    {

        bubble2 = new Bubble2(stage);
        bubble2.x = xCoordinate;
        bubble2.y = yCoordinate;
        bubble2.xDirection = xDir;
        bubble2.yDirection = yDir;
        Engine.bubbles2.push(bubble2);
        stageRef.addChild(bubble2);

    }

}

}

Answer 1

据推测，bubbles数组返回一个空值。您是否尝试过追踪bubbles1数组中的值。

public function bounce(event:Event):void
{
    for (var i:uint = 0; i < bubbles1.length; i++)
    {
       // log out the value from your array
       trace("bubble " + bubbles1[i]);
    }
}

尝试启动补间会返回空对象引用

1 个答案: