好的，首先让我说这是我的第一个 AS3 项目。我对 Java 没问题，所以 OOP 和继承对我来说并不陌生。我确实花了几个小时坐在这里思考为什么我的代码没有像我想要的那样工作。我从一个试图发射子弹的炮塔开始。然而，子弹并没有被绘制到屏幕上，即使 x 和 y 坐标仍在变化。创建子弹/弹丸的方法称为 OnMouseClick。这是我的代码：
public class Main extends Sprite
{
public var projectileArr : Array = new Array(); //array which the projectile objects are stored
public var projCount : Number = 0; //projectile counter
public var curX:Number; //mouse coords
public var curY:Number;
private var tri1:Sprite = new Sprite();
private var tri1Height:Number = 50;
private var rect1:Sprite = new Sprite();
private var rect1W:Number = 2;
private var rect1H:Number = 10;
private var angle:Number = 0;
private var acceleration:Number = 0;
public var triSpeedX:Number = 0;
public var triSpeedY:Number = 0;
public var turretAngle:Number ;
//keyboard booleans
private var leftDown:Boolean = false, rightDown:Boolean = false, upDown:Boolean = false, downDown:Boolean = false;
public function Main():void
{
if (stage)
init();
else
addEventListener(Event.ADDED_TO_STAGE, init);
}
private function init(e:Event = null):void
{
removeEventListener(Event.ADDED_TO_STAGE, init);
// entry point
//draw triangle
addChild(tri1);
tri1.graphics.lineStyle(1, 0xff00ff00);
tri1.graphics.beginFill(0xff0000);
tri1.graphics.moveTo(0, -tri1Height / 2)
tri1.graphics.lineTo(tri1Height / 3, +tri1Height / 2);
tri1.graphics.lineTo(-tri1Height / 3, +tri1Height / 2);
tri1.graphics.endFill();
tri1.x = 400;
tri1.y = 300;
//draw turret
addChild(rect1);
rect1.graphics.beginFill(0xFFFFFF);
rect1.graphics.moveTo(rect1W / 2, -rect1H);
rect1.graphics.lineTo(rect1W / 2, 0);
rect1.graphics.lineTo(-rect1W / 2, 0);
rect1.graphics.lineTo(-rect1W / 2, -rect1H);
rect1.graphics.endFill();
rect1.x = tri1.x;
rect1.y = tri1.y;
stage.addEventListener(KeyboardEvent.KEY_UP, onUp);
stage.addEventListener(KeyboardEvent.KEY_DOWN, onDown);
stage.addEventListener(Event.ENTER_FRAME, Run);
stage.addEventListener(MouseEvent.MOUSE_MOVE, getMouseCoord);
stage.addEventListener(MouseEvent.MOUSE_DOWN, OnMouseClick);
}
//creation of projectile on click
public function OnMouseClick (e:MouseEvent):void
{
projectileArr[projCount] = new Projectile (rect1.x, rect1.y, turretAngle); //create a new projectile object
addChild(projectileArr [projCount]); //... then it doesn't display
projCount++;
trace ("BAM");
}
public function getMouseCoord(e:MouseEvent):void
{
curX = mouseX;
curY = mouseY;
}
public function onUp(e:KeyboardEvent):void
{
if (e.keyCode == Keyboard.LEFT)
leftDown = false;
else if (e.keyCode == Keyboard.RIGHT)
rightDown = false;
if (e.keyCode == Keyboard.UP)
upDown = false;
else if (e.keyCode == Keyboard.DOWN)
downDown = false;
}
public function onDown(e:KeyboardEvent):void
{
if (e.keyCode == Keyboard.LEFT)
leftDown = true;
else if (e.keyCode == Keyboard.RIGHT)
rightDown = true;
if (e.keyCode == Keyboard.UP)
upDown = true;
else if (e.keyCode == Keyboard.DOWN)
downDown = true;
}
public function addProjToScreen (projectile:Projectile) : void
{
addChild(projectile);
}
private function Run(e:Event):void
{
acceleration = 0; //resets acceleration back to 0 to limit speed
if (leftDown)
{
angle -= 5;
}
else if (rightDown)
{
angle += 5;
}
if (upDown)
{
acceleration += 3;
}
else if (downDown)
{
acceleration -= 3;
}
triSpeedX += acceleration * Math.cos(angle * Math.PI / 180);
triSpeedY += acceleration * Math.sin(angle * Math.PI / 180);
tri1.x += triSpeedX;
tri1.y += triSpeedY;
//borders
if (tri1.x < 0)
{
triSpeedX *= -.5;
tri1.x = 0 ;
}
if (tri1.x > 800 )
{
tri1.x = 800;
triSpeedX *= -.5;
}
if (tri1.y < 0)
{
triSpeedY *= -.5;
tri1.y = 0 ;
}
if (tri1.y > 600)
{
triSpeedY *= -.5;
tri1.y = 600;
}
//friction
triSpeedX *= 0.95
triSpeedY *= 0.95
rect1.x = tri1.x;
rect1.y = tri1.y;
var xCurDist:Number = curX - rect1.x;
var yCurDist:Number = curY - rect1.y;
turretAngle = Math.atan(yCurDist / xCurDist) * 180 / Math.PI ;
if (xCurDist < 0 )
{
turretAngle += 180;
}
if (xCurDist > 0 && yCurDist < 0 )
{
turretAngle += 360;
}
rect1.rotation= turretAngle + 90; // + 90 to account for the sprite originally pointing up, which is 270 degrees ccw
tri1.rotation = angle + 90;
for (var i:int = 0 ; i < projCount ; i ++)
{
projectileArr [i].move();
}
}
}
和 Projectile 类：
public class Projectile extends MovieClip
{
private var projectile : Sprite = new Sprite();
private var speed: int = 10;
private var angle :Number;
private var xIncr: Number;
private var yIncr: Number;
public function Projectile(x:Number, y:Number, angle:Number)
{
this.x = x;
this.y = y;
this.angle = angle;
projectile.graphics.beginFill (0xFF0000);
projectile.graphics.drawCircle (x, y, 4);
projectile.graphics.endFill() ;
xIncr = speed * Math.cos (angle); // angle needs to be converted to radians
yIncr = speed * Math.sin (angle);
}
public function move () :void
{
trace (this.x + " " + this.y);
this.x += xIncr;
this.y += yIncr;
}
}
我只是不知道我错过了什么......我正在为我所有新创建的对象调用 addChild，还有什么可做的？