我如何在动作面板中编码一个对象来生成到舞台上?

Question

我正尝试在我的乒乓游戏中引入一种新球，有点像加力球。我在第一帧的动作面板中编写所有代码。新球应该出现在舞台上，并开始像原来的球一样随机移动。虽然我使用的是代码片段，而不是.as文件。所以我所有的代码是在动作面板(通过按f9访问)。

我还希望我的动态文本框与舞台颜色合并，这样你就看不到白色的背景。

我不能给你看fla是什么样子的，因为我的声誉不到10，但是动态文本框不会合并到背景中，而是有一个白色的周围。当球上升时，这样可以隐藏球。

import flash.events.Event;
import flash.ui.Mouse;
//hide mouse
Mouse.hide();



init(); //initialises everything
var bSpeedX:int = -3.5;
var bSpeedY:int = -2.5;

// assign a maximum speed to the AI 
var compPaddleSpeed:int = 3.5; 
var pScore:int = 0;
var cScore:int = 0;


// Updates the score
function scoreUpdate():void {
    playerScore.text = ("Player Score: " + pScore);
    computerScore.text = ("AI Score: " + cScore);

}


function init():void //tells flash not to return values
{ 
    stage.addEventListener(Event.ENTER_FRAME, loop);
}   
/*we want the ySpeed to be larger if there 
is a greater difference between the y 
positions of the ball and paddle, so I started with 
(gameBallY-padY). To convert this difference 
into a number between -1 and 1, I divided 
this number by 25, which 
is half the height of the paddle. Finally, I wanted 
the ySpeed to be more powerful than 
just -1 to 1, and after a bit of trial and error 
I decided to times by 5 at the end 
to change the total magnitude of the new ySpeed.*/

//defying the laws of Physics
function calculategameBallAngle(padY:Number, gameBallY:Number):Number
{
    var ySpeed:Number = 5 * ((gameBallY-padY) / 25 );
    return ySpeed;
}


//main loop 
function loop(e:Event):void
{   
    //makes the paddle track the mouse
    playerPaddle.y = mouseY;
    //paddle AI
    if(compPaddle.y < gameBall.y - 10){ 
        compPaddle.y += compPaddleSpeed;//make it go up
    } else if(compPaddle.y > gameBall.y + 10){ 
        compPaddle.y -= compPaddleSpeed;//make it go down
    }
    //Collisions
    if( playerPaddle.hitTestObject(gameBall) == true ){
    if(bSpeedX < 0){
        bSpeedX *= -1;
        bSpeedY = calculategameBallAngle(playerPaddle.y, gameBall.y);
    }
} else if(compPaddle.hitTestObject(gameBall) == true ){ 
    if(bSpeedX > 0){
        bSpeedX *= -1;
        bSpeedY = calculategameBallAngle(compPaddle.y, gameBall.y);
    }
}

    //makes the gameBall move 
    gameBall.x += bSpeedX; //each frame, we add the bSpeedX to the ball's x position.
    gameBall.y += bSpeedY; //same for the bSpeedY to the ball's y postion.

    // checks to see if the ball misses the paddle 
    if(gameBall.x <= gameBall.width/2){
       gameBall.x = gameBall.width/2;
       bSpeedX *= -1;
       cScore ++;
       scoreUpdate();

    //keeps the ball within the stage
    } else if(gameBall.x >= stage.stageWidth-gameBall.width/2){
        gameBall.x = stage.stageWidth-gameBall.width/2;
        bSpeedX *= -1;
        pScore ++;
        scoreUpdate();

    }
    if(gameBall.y <= gameBall.height/2){
        gameBall.y = gameBall.height/2;
        bSpeedY *= -1;
    }
    else if(gameBall.y >= stage.stageHeight-gameBall.height/2){
        gameBall.y = stage.stageHeight-gameBall.height/2;
        bSpeedY *= -1;
    }
 //-------------------------------------------------------

    //keeps the player paddle within the stage
    //check if paddle is above top of the screen 
    if(playerPaddle.y - playerPaddle.height/2 < 0){
        playerPaddle.y = playerPaddle.height/2;
    } else if(playerPaddle.y + playerPaddle.hieght/2 > stage.stageHeight){
        playerPaddle.y = stage.stageHeight - playerPaddle.height/2;

    //check if paddle is below bottom of the screen
    } else if(playerPaddle.y + playerPaddle.height/2 > stage.stageHeight){
     playerPaddle.y = stage.stageHeight - playerPaddle.height/2;
  }
    }

Answer 1

如果你只想让你的球被替换成一个具有不同图形和/或速度的新球，你可以将你的球类导出到动作脚本:

Library>RMB on your symbol>Properties>ActionScript Linkage>Export for ActionScript

在Class:字段下键入您的类名，如"MyBallClass"，然后点击OK。

现在你可以在你的代码中构造这个球，并像这样替换旧的:

var newBall:MyBallClass = new MyBallClass();
addChild(newBall);
newBall.x = gameBall.x; newBall.y = gameBall.y;
gameBall = newBall;

另外，您可以定义像var speedModifier:Number = 1;这样的新变量来使用:

gameBall.x += bSpeedX * speedModifier;
gameBall.y += bSpeedY * speedModifier;

当你改变球的时候也要改变它

如果你想同时拥有多个球，你真的应该考虑在OOP中构建它。这是一个最简单的例子你可以创建MyBallClass。作为文件并在其中写入如下内容:

package  
{
    import flash.display.Sprite;
    import flash.geom.Point;
    public class MyBallClass extends Sprite
    {
        public var speedFactor:Number;
        public var speed:Point = new Point(-3.5, -2.5);
        public function MyBallClass(x:Number, y:Number, speedFactor:Number = 1) 
        {
            this.x = x; this.y = y;
            this.speed = speed;
        }
    }
}

现在你可以为你的游戏中所有的球创建一个容器。

var balls:Vector<MyBallClass> = Vector<MyBallClass>([]);

并在循环中为所有这些运行物理。

通常主代码看起来像这样:

var balls:Vector.<MyBallClass> = Vector.<MyBallClass>([]);
addBall(...)//place first ball.
function loop(e:Event):void {
    processBalls();
    if(wantToAddNewSuperSpeedBall) addBall(x,y,3);
    ...
}
function processBalls() {
    for (var i:int = 0; i < balls.length; i++) {
        detecCollision(balls[i]);
        moveBall(balls[i]);
        //any code that process a single ball...
    }
}
function addBall(x:Number, y:Number, speedFactor:Number = 1) {
    var newBall:MyBallClass = new MyBallClass(x,y, speedFactor);
    addChild(newBall);
    balls.push(newBall);
}
function moveBall(ball:MyBallClass) {
    ball.x += ball.speed.x * ball.speedFactor;
    ball.y += ball.speed.y * ball.speedFactor;
}

所以你应该修改所有影响球行为的函数，让球作为参数传递，而不仅仅是一个特定的实例，然后对所有的球使用它们。

在这个主题中有更多要涵盖的内容，这可能不是最好的方法，但我已经尽力使其易于理解。有很多关于OOP的指南，因此如果您阅读它们，您可以更好地了解正在发生的事情。我希望这对你有所帮助。