常用的AS3代码

常用的一些代码段，摘自AS3游戏编程大学(ActionScript 3.0 Game Programming University),如果转载，请注明出处--Arthur。
1、检测碰撞

addEventListener(Event.ENTER_FRAME, checkCollision);

function checkCollision(event:Event) {

 //hitTestPoint检测对象与某点是否发生碰撞

 if (crescent.hitTestPoint(mouseX, mouseY, true)) {

 messageText1.text = "hitTestPoint: YES";

 } else {

 messageText1.text = "hitTestPoint: NO";

 } 

 // move star with mouse

 star.x = mouseX;

 star.y = mouseY; 

 //hitTestObject检测两物体是否碰撞

 if (star.hitTestObject(crescent)) {

 messageText2.text = "hitTestObject: YES";

 } else {

 messageText2.text = "hitTestObject: NO";

 }

}

2、使用文本框

//创建基本格式

var myFormat:TextFormat = new TextFormat();

myFormat.font = "Arial";

myFormat.size = 24;

myFormat.bold = true;

//创建样式表

var myStyleSheet:StyleSheet = new StyleSheet();

myStyleSheet.setStyle("A",{textDecoration: "underline", color: "#0000FF"});

var myLink:TextField = new TextField();

//使用格式化文本

myLink.defaultTextFormat = myFormat;

//文本使用样式表

myLink.styleSheet = myStyleSheet;

myLink.selectable = false;

myLink.htmlText = "Click <A HREF='event:testing'>here</A>";

myLink.x = 80;

myLink.y = 190;

myLink.width = 400;

myLink.height = 30;

addChild(myLink);

//添加文本单击事件

addEventListener(TextEvent.LINK, textLinkClick);

function textLinkClick(event:TextEvent) {

 trace(event.text);

}

3、使用自定义鼠标

Mouse.hide();

addEventListener(Event.ENTER_FRAME, moveCursor);

arrow.mouseEnabled = false;

function moveCursor(event:Event) {

 arrow.x = mouseX;

 arrow.y = mouseY;

}

4、简单计数器

var timeDisplay:TextField = new TextField();

addChild(timeDisplay);

var startTime:int = getTimer();

addEventListener(Event.ENTER_FRAME, showClock);

function showClock(event:Event) {

 var timePassed:int = getTimer()-startTime;

 var seconds:int = Math.floor(timePassed/1000);

 var minutes:int = Math.floor(seconds/60);

 seconds -= minutes*60;

 var timeString:String = minutes+":"+String(seconds+100).substr(1,2);

 timeDisplay.text = timeString;

5、拖动影片

mascot.addEventListener(MouseEvent.MOUSE_DOWN, startMascotDrag);

stage.addEventListener(MouseEvent.MOUSE_UP, stopMascotDrag);

mascot.addEventListener(Event.ENTER_FRAME, dragMascot);

var clickOffset:Point = null;

function startMascotDrag(event:MouseEvent) {

 clickOffset = new Point(event.localX, event.localY);

}

function stopMascotDrag(event:MouseEvent) {

 clickOffset = null;

}

function dragMascot(event:Event) {

 if (clickOffset != null) { // must be dragging

 mascot.x = mouseX - clickOffset.x;

 mascot.y = mouseY - clickOffset.y;

 }

}

6、使用动态绘图函数

// 画(100,200)到(150,250)的直线

this.graphics.lineStyle(2,0x000000);

this.graphics.moveTo(100,200);

this.graphics.lineTo(150,250);

// 画曲线

this.graphics.curveTo(200,300,250,250);

// 画矩形、圆角矩形

this.graphics.drawRect(50,50,300,250);

this.graphics.drawRoundRect(40,40,320,270,25,25);

// 画圆、椭圆

this.graphics.drawCircle(150,100,20);

this.graphics.drawEllipse(180,150,40,70);

// 填充圆

this.graphics.beginFill(0x333333);

this.graphics.drawCircle(250,100,20);

this.graphics.endFill();

7、捕捉键盘输入

// 显示按下的键

var keyboardText:TextField = new TextField();

keyboardText.selectable = false;

addChild(keyboardText);

//用于显示spacbar是否按下

var spacebarText:TextField = new TextField();

spacebarText.selectable = false;

spacebarText.y = 30;

addChild(spacebarText);

spacebarText.text = "Spacebar is UP.";

var spacebarPressed:Boolean = false;

stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDownFunction);

function keyDownFunction(event:KeyboardEvent) {

 keyboardText.text = "Key Pressed: "+String.fromCharCode(event.charCode);

 if (event.charCode == 32) {

 spacebarPressed = true;

 spacebarText.text = "Spacebar is DOWN.";

 }

}

stage.addEventListener(KeyboardEvent.KEY_UP, keyUpFunction);

function keyUpFunction(event:KeyboardEvent) {

 if (event.charCode == 32) {

 spacebarPressed = false;

 spacebarText.text = "Spacebar is UP.";

 }

}

8、加载HTML页面变量(difficultyLevel变量由HTML'flashvars'设置)

var paramObj:Object = LoaderInfo(this.root.loaderInfo).parameters;

var diffLevel:String = paramObj["difficultyLevel"];

var messageString = "difficultyLevel: "+paramObj["difficultyLevel"];

messageString += "\n";

messageString += "puzzleFile: "+paramObj["puzzleFile"];

messageText.text = messageString;

9、加载外部XML格式文本

var xmlURL:URLRequest = new URLRequest("LoadingData.xml");

var xmlLoader:URLLoader = new URLLoader(xmlURL);

xmlLoader.addEventListener(Event.COMPLETE, xmlLoaded);

function xmlLoaded(event:Event) {

 var dataXML = XML(event.target.data);

 trace(dataXML.question.text);

 trace(dataXML.question.answers.answer[0]);

 trace(dataXML.question.answers.answer[0].@type);

}

10、建立预加载动画

stop();

addEventListener(Event.ENTER_FRAME, loadProgress);

function loadProgress(event:Event) {

 // 获得总字节数和已经加载的字节数

 var movieBytesLoaded:int = this.root.loaderInfo.bytesLoaded;

 var movieBytesTotal:int = this.root.loaderInfo.bytesTotal;

 // 转化为MB

 var movieKLoaded:int = movieBytesLoaded/1024;

 var movieKTotal:int = movieBytesTotal/1024;

 progressText.text = "Loading: "+movieKLoaded+"K/"+movieKTotal+"K";

 if (movieBytesLoaded >= movieBytesTotal) {

 removeEventListener(Event.ENTER_FRAME, loadProgress);

 gotoAndStop(2);

 }

}

11、动态建立按钮元件
函数：SimpleButton(upState:DisplayObject = null, overState:DisplayObject = null,

downState:DisplayObject = null, hitTestState:DisplayObject = null)

var mySimpleButton:SimpleButton = new SimpleButton(new ButtonUp(), new ButtonOver(), new 


ButtonDown(), new ButtonHit());

mySimpleButton.x = 450;

mySimpleButton.y = 250;

addChild(mySimpleButton);

mySimpleButton.addEventListener(MouseEvent.CLICK, clickSimpleButton);

function clickSimpleButton(event:MouseEvent) {

 trace("You clicked the simple button!");

}

12、使用声音

button1.addEventListener(MouseEvent.CLICK, playLibrarySound);

button2.addEventListener(MouseEvent.CLICK, playExternalSound);

// 加载外部声音

var sound2:Sound = new Sound();

var req:URLRequest = new URLRequest("PlayingSounds.mp3");

sound2.load(req);

function playLibrarySound(event:Event) {

 var sound1:Sound1 = new Sound1();

 var channel:SoundChannel = sound1.play();

}

function playExternalSound(event:Event) {

 sound2.play();

}

13、生成随机数

var random1:Number = Math.random();

trace("Random Number Between 0-0.9999: "+random1);

var random2:Number = Math.random()*100;

trace("Random Number Between 0-99.9999: "+random2);

var random3:Number = Math.floor(Math.random()*100);

trace("Random Integer Between 0-99: "+random3);

var random4:Number = Math.floor(Math.random()*100)+1;

trace("Random Integer Between 1-100: "+random4);

14、存储数据

var myLocalData:SharedObject = SharedObject.getLocal("mygamedata");

trace("Found Data: "+myLocalData.data.gameinfo);

myLocalData.data.gameinfo = "Store this.";

15、随机排列数组元素

// 创建有序的数组

var startDeck:Array = new Array();

for(var cardNum:int=0;cardNum<52;cardNum++) {

 startDeck.push(cardNum);

}

trace("Unshuffled:",startDeck);

// 打乱数据

var shuffledDeck:Array = new Array();

while (startDeck.length > 0) {

 var r:int = Math.floor(Math.random()*startDeck.length);

 shuffledDeck.push(startDeck[r]);

 startDeck.splice(r,1);

}

trace("Shuffled:", shuffledDeck);

16、获取环境信息

function showInfo(event:Event) {

 var output:String = "";

 output += "stageWidth: "+stage.stageWidth+"\n";

 output += "stageHeight: "+stage.stageHeight+"\n";

 output += "playerType: "+Capabilities.playerType+"\n";

 output += "language: "+Capabilities.language+"\n";

 output += "os: "+Capabilities.os+"\n";

 output += "screenResolutionX: "+Capabilities.screenResolutionX+"\n";

 output += "screenResolutionY: "+Capabilities.screenResolutionY+"\n";

 output += "version: "+Capabilities.version+"\n";

 output += "serverString: "+Capabilities.serverString+"\n";

 messageText.text = output;

}

stage.scaleMode = StageScaleMode.EXACT_FIT;

addEventListener(Event.ENTER_FRAME,showInfo);

17、接受文本输入

myInput.addEventListener(KeyboardEvent.KEY_UP, checkForReturn);

function checkForReturn(event:KeyboardEvent) {

 if (event.charCode == 13) {

 acceptInput();

 }

}

function acceptInput() {

 var theInputText:String = myInput.text;

 trace(theInputText);

 removeChild(myInput);

}