Actionscript - 随机水平移动掉落物体

Posted 2023-02-18

【中文标题】Actionscript - 随机水平移动掉落物体

【英文标题】：Actionscript - Random Horizontal Movement Dropping Objects

【发布时间】：2012-04-09 13:18:14

【问题描述】：

我正在为我的动作脚本类制作类似于 Kaboom 的游戏

http://www.groovz.com/play/kaboom/

我意识到我还没有接近完成，它可能很糟糕，但这是我到目前为止的代码：

var bucket:Bucket=new Bucket
var sun:Sun=new Sun
var fireBalls:Array=new Array()
var livesLeft:Array=new Array()
addChild(bucket)
addChild(sun)
sun.x=sun.width/2
sun.y=50
bucket.x=bucket.width/2
bucket.y=stage.stageHeight-50
bucket.speed=15

stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown)

function onKeyDown(event:KeyboardEvent)
    if (event.keyCode==37&&bucket.x>bucket.width/2) // left arrow key
        bucket.x=bucket.x-bucket.speed;
    
    if (event.keyCode==39&&bucket.x<stage.stageWidth-bucket.width/2) // right arrow key
        bucket.x=bucket.x+bucket.speed;
    


stage.addEventListener(MouseEvent.MOUSE_MOVE,followBucket);

function followBucket(event:MouseEvent):void 
bucket.x=mouseX;


addEventListener(Event.ENTER_FRAME,onEnterFrame)

function checkForCollisions ()



function onEnterFrame(event:Event)
    checkForCollisions.call();
    sun.x=sun.x+15;
    if (fireBalls.length>0&&fireBalls[0].y>stage.stageHeight-20) // Fireballs exit stage
        removeChild(fireBalls[0]);
        fireBalls.shift();
    
    for (var j:int=0; j<fireBalls.length; j++)
        fireBalls[j].y=fireBalls[j].y+15;
        if (fireBalls[j].y>stage.stageHeight-fireBall.width/2)
        
       
    if (Math.random()>.2) // Fireballs shooting from Sun
        var fireBall:FireBall=new FireBall;
        fireBall.x=sun.x;
        addChild(fireBall);
        fireBalls.push(fireBall);
    
    if (sun.x>stage.stageWidth) // Sun hits right side of stage
        sun.x=0;
    
    if (sun.x<0) // Sun hits left side of stage
        sun.x=stage.stageWidth;
    

我知道我想使用计时器事件或其他东西让太阳随机切换方向，但我不太明白，建议？

这是一个关于 swf 的概念（在这个模拟中它没有加载所有内容，桶在舞台上并在现实中左右移动 onKeyDown）：

http://www.shareswf.com/game/24222/kaboom-sun-clone

【参考方案1】：

像这样

import flash.events.TimerEvent;
import flash.utils.Timer;
var bucket:Bucket=new Bucket
var sun:Sun=new Sun
var fireBalls:Array=new Array()
var livesLeft:Array = new Array()
var left:Boolean;
var timer:Timer = new Timer(1000); // test change direction every second


addChild(bucket)
addChild(sun)
sun.x=sun.width/2
sun.y=50
bucket.x=bucket.width/2
bucket.y=stage.stageHeight-50
bucket.speed=15

stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown)

function onTimer(e:TimerEvent) 
    left = (Math.random() > 0.5);// 50/50 chance of changing direction



timer.addEventListener(TimerEvent.TIMER, onTimer);
timer.start();

function onKeyDown(event:KeyboardEvent)
    if (event.keyCode==37&&bucket.x>bucket.width/2) // left arrow key
        bucket.x=bucket.x-bucket.speed;
    
    if (event.keyCode==39&&bucket.x<stage.stageWidth-bucket.width/2) // right arrow key
        bucket.x=bucket.x+bucket.speed;
    


stage.addEventListener(MouseEvent.MOUSE_MOVE,followBucket);

function followBucket(event:MouseEvent):void 
bucket.x=mouseX;


addEventListener(Event.ENTER_FRAME,onEnterFrame)

function checkForCollisions ()



function onEnterFrame(event:Event)
    checkForCollisions.call();
    if (left) 
        sun.x = sun.x - 15;
    else
        sun.x = sun.x + 15;
    
    if (fireBalls.length>0&&fireBalls[0].y>stage.stageHeight-20) // Fireballs exit stage
        removeChild(fireBalls[0]);
        fireBalls.shift();
    
    for (var j:int=0; j<fireBalls.length; j++)
        fireBalls[j].y=fireBalls[j].y+15;
        if (fireBalls[j].y>stage.stageHeight-fireBall.width/2)
        
       
    if (Math.random()>.2) // Fireballs shooting from Sun
        var fireBall:FireBall=new FireBall;
        fireBall.x=sun.x;
        addChild(fireBall);
        fireBalls.push(fireBall);
    
    if (sun.x>stage.stageWidth) // Sun hits right side of stage
        sun.x=0;
    
    if (sun.x<0) // Sun hits left side of stage
        sun.x=stage.stageWidth;
    

【讨论】：

感谢这很好用，现在我有最后一个问题：如何让火球更频繁地掉落？我假设我使用 Math.random 不正确？还是等待 1 从数组中删除，然后再删除另一个？

运行您链接到的 swf，我得到一个空引用错误。我认为您代码中其他地方的错误正在使脚本崩溃。

是的，我认为 null 引用是 fireBalls 数组，我在这里提出了一个新问题：***.com/questions/9866132/…