AS3 CookBook学习整理(三)

1. 在可视化对象列表中添加项目

Flash Player 现在把ActionScript 虚拟机(AVM)和渲染引擎两块功能集成在一起了。AVM 完成执行ActionScript 代码，而渲染引擎负责在屏幕上绘制对象，绘制对象需要两步骤：通过ActionScript引擎创建可视化对象。渲染引擎把可视化对象绘制在屏幕上

AVM中创建了一个可视化对象后，并没有绘制在屏幕上，因为它还不存在于渲染引擎里，要把它放到渲染引擎里需要添加该对象到可视化对象列表，通过调用DisplayObjectContainer实例的addChild()或addChildAt()方法添加

package

 {

import

flash.display.Shape;

import

flash.display.Sprite;

public class

 Sample1120

extends

Sprite
{

public function

 Sample1120()
{

var

red:Shape = 

new

Shape();

var

green:Shape = 

new

Shape();

var

blue:Shape = 

new

Shape();
red.graphics.beginFill(0xFF0000);
red.graphics.drawCircle(10,20,10);
red.graphics.endFill();
green.graphics.beginFill(0x00FF00);
green.graphics.drawCircle(15,25,10);
green.graphics.endFill();
blue.graphics.beginFill(0x0000FF);
blue.graphics.drawCircle(20,20,10);
blue.graphics.endFill();
stage.addChild(red);
stage.addChild(green);
stage.addChildAt(blue,2);

//下面演示重复添加同一对象

//var container1:Sprite = new Sprite();

//container1.addChild(red);

//container1.addChild(green);

//container1.addChild(blue);

//this.addChild(container1);

//var container2:Sprite = new Sprite();

//container2.addChild(red);

//this.addChild(container2);

 
}
}
}

2. 在可视化对象列表中删除项目

使用DisplayObectContainer类的removeChild()和removeChildAt()方法

package

 {

import

flash.display.DisplayObjectContainer;

import

flash.display.Sprite;

import

flash.text.TextField;

public class

 Sample1120

extends

Sprite
{

public function

 Sample1120()
{

this

.addChild(

new

TextField());

this

.addChild(

new

TextField());

this

.addChild(

new

TextField());

trace

(

"删除前："

+

this

.numChildren);
RemoveAllElement(

this

);

trace

(

"删除后："

+

this

.numChildren);
}

private function

 RemoveAllElement(container:DisplayObjectContainer):

void

{

var

length:int = container.numChildren;

for

(

var

i:int=0;i<length;i++)
{

this

.removeChildAt(0);
}
}
}
}

3. 在可视化对象列表中移动对象位置

使用DisplayObectContainer类的setChildIndex()方法改变项目的位置，getChildIndex()和getChildAt()方法得到项目在显示列表中的位置。getChildIndex()返回当前对象的索引，getChildAt()返回当前对象的引用

package

 {

import

flash.display.Shape;

import

flash.display.Sprite;

import

flash.events.MouseEvent;

public class

 Sample1120

extends

Sprite
{

public function

 Sample1120()
{

var

arrColor:Array = [0xFF0000,0x00FF00,0x0000FF,0xFFFF00,0x00FFFF];
stage.addEventListener(MouseEvent.CLICK,OnClick);

for

(

var

i:int=0; i<arrColor.length;i++)
{

var

shape:Shape = AddElement(arrColor[i]);
shape.x = i*3+20;
shape.y = 20;
}
}

private function

 AddElement(color:int):Shape
{

var

shape:Shape = 

new

Shape();
shape.graphics.beginFill(color);
shape.graphics.drawCircle(10,10,30);
shape.graphics.endFill();

this

.addChild(shape);

return

 shape;
}

private function

 OnClick(event:MouseEvent):

void

{

this

.setChildIndex(

this

.getChildAt(0),

this

.numChildren-1);
}
}
}

4. 创建自定义可视化类

继承DisplayObject 或它的子类来创建新类

package

 {

import

flash.display.Shape;

import

flash.display.Sprite;

public class

 Sample1121

extends

Sprite
{

public function

 Sample1121()
{

var

_circle:Circle = 

new

Circle(0xFF0000,80);
_circle.x = 100;
_circle.y = 100;
addChild(_circle);
}
}
}

import

flash.display.Shape;

internal class

 Circle

extends

Shape
{

private var

_color:uint;

private var

_radius:uint;

public function

 Circle(color:uint=0x000000,radius:uint=10)
{
_color = color;
_radius = radius;
Draw();
}

private function

 Draw():

void

{
graphics.beginFill(_color);
graphics.drawCircle(0,0,_radius);
graphics.endFill();
}
}

5. 创建简单的按钮 

package
{
    import flash.display.Sprite;
    import flash.display.StageScaleMode;
    import flash.events.MouseEvent;

    public class Test extends Sprite
    {
        public function Test()
        {
            stage.scaleMode = StageScaleMode.NO_SCALE;
            var button1:MyButton = new MyButton("确 定");
            button1.addEventListener(MouseEvent.CLICK,onClick);
            this.addChild(button1);
        }
        
        private function onClick(event:MouseEvent):void
        {
            trace("click");
        }
    }
}

import flash.display.Sprite;
import flash.events.MouseEvent;
import flash.text.TextField;
import flash.text.TextFieldAutoSize;
import flash.text.TextFormat;

internal class MyButton extends Sprite
{
    private var button:Sprite;
    private var label:TextField;
    private var textFormat:TextFormat;
    
    private var _text:String;
    private var _width:Number;
    private var _height:Number;
    private var _bgColor:uint;
    private var _fontColor:uint;
    private var _overBgColor:uint;
    private var _overFontColor:uint;
    
    public function MyButton(text:String,width:Number=85,height:Number=30,bgColor:uint=0x14B9F8,fontColor:uint=0xFFFFFF,overBgColor:uint=0x2BC4FE,overFontColor:uint=0xFFFFFF)
    {
        this._text = text;
        this._width = width;
        this._height = height;
        this._bgColor = bgColor;
        this._fontColor = fontColor;
        this._overBgColor = overBgColor;
        this._overFontColor = overFontColor;
        
        button = new Sprite();
        button.graphics.beginFill(this._bgColor);
        button.graphics.drawRoundRect(0,0,this._width,this._height,10,10);
        button.graphics.endFill();
        this.addChild(button);
        
        label = new TextField();
        label.autoSize = TextFieldAutoSize.CENTER;
        label.selectable = false;
        label.mouseEnabled = false;
        textFormat = new TextFormat();   
        textFormat.color = this._fontColor;
        textFormat.size = 16;
        label.defaultTextFormat = textFormat;
        label.text = this._text;
        label.x = (button.width-label.width)/2;
        label.y = (button.height-label.height)/2+1;
        button.addChild(label);
        
        //mask
        var maskRect:Sprite = new Sprite();
        maskRect.graphics.beginFill(0xFFFF00,0);
        maskRect.graphics.drawRoundRect(0,0,this._width,this._height,10,10);
        maskRect.graphics.endFill();
        maskRect.addEventListener(MouseEvent.MOUSE_OVER,button_mouseOverHandler);
        maskRect.addEventListener(MouseEvent.MOUSE_OUT,button_mouseOutHandler);
        maskRect.buttonMode = true;
        this.addChild(maskRect);
    }
    
    private function button_mouseOverHandler(event:MouseEvent):void
    {
        button.graphics.clear();
        button.graphics.beginFill(this._overBgColor);
        button.graphics.drawRoundRect(0,0,this._width,this._height,10,10);
        button.graphics.endFill();
        
        textFormat = new TextFormat();   
        textFormat.color = this._overFontColor;            
        textFormat.size = 16;
        label.defaultTextFormat = textFormat;
        label.text = this._text;
    }
    
    private function button_mouseOutHandler(event:MouseEvent):void
    {
        button.graphics.clear();
        button.graphics.beginFill(this._bgColor);
        button.graphics.drawRoundRect(0,0,this._width,this._height,10,10);
        button.graphics.endFill();
        
        textFormat = new TextFormat();   
        textFormat.color = this._fontColor;            
        textFormat.size = 16;
        label.defaultTextFormat = textFormat;
        label.text = this._text;
    }
}

Code