一個很常用的資料表示方式
為了方便以後使用
所以乾脆就寫成一個CLASS

調用的時候只要

var itemCocept:scrollText = new scrollText(width, height, TXT);
addChild(itemCocept);

當文字內容超過指定的高度
就會自動生成scroll bar

package justfly.vo{

	import flash.events.*;
	import flash.display.*;
	import flash.text.TextField;
    import flash.text.TextFormat;
    import flash.text.TextFieldAutoSize;
    import flash.text.AntiAliasType;
    import flash.text.GridFitType;
	import flash.geom.Rectangle;
	
	import caurina.transitions.Tweener;
	
	import justfly.dao.*;
	import justfly.ui.*;
	import justfly.util.*;
	import justfly.vo.*;
	
	public class scrollText extends Sprite {
		var mod:ModelLocator = ModelLocator.getInstance();
		
		var areaH:int;
		var areaW:int;
		var mainString:String;
		
		var format:TextFormat = new TextFormat();
		var mask_scrollText:Sprite;
		var tab_bar:Sprite;
		var Rec:Rectangle;
		var avable:int;
		var nowhave:int;
		
		var conceptTxt:TextField;
		var pix:int = 10;
		
		public function scrollText(w:int, h:int, txt:String) { 
			areaH = h;
			areaW = w;
			mainString = txt;
			addEventListener(Event.ADDED_TO_STAGE, init);
		}
		
		private function init(e:Event) {	
			removeEventListener(Event.ADDED_TO_STAGE, init);
			
			format.size = 11;
			conceptTxt = createTextField(0, 0, format, mainString, TextFieldAutoSize.LEFT, GridFitType.PIXEL);
			
			mask_scrollText = new Sprite();
			mask_scrollText.graphics.beginFill(0x000000);
			mask_scrollText.graphics.drawRect(0, 0,  areaW, areaH);
			mask_scrollText.graphics.endFill();
			addChild(mask_scrollText);
			mask = mask_scrollText;
						
			if (conceptTxt.height > areaH) setScroll();
		}
		
		private function createTextField(x:Number,y:Number,fm:TextFormat,tl:String,tfs:String,gft:String):TextField 
        {
            var result:TextField = new TextField();
			result.textColor = 0xFFFFFF;
            result.x = x;
            result.y = y;
            //result.embedFonts = true;
			result.wordWrap = true;
			result.selectable = false;
            result.antiAliasType = AntiAliasType.ADVANCED;
            result.text = tl;
            result.autoSize = tfs;
			result.gridFitType = gft;
            result.setTextFormat(fm);
			result.width = areaW;
            addChild(result);
			
            return result;
        }
		
		private function setScroll() {
			Tweener.addTween(conceptTxt, { width: areaW - 10, time:0.2, transition:"linear", onComplete:function() {
				avable = Math.floor(areaH / pix);
				nowhave = Math.floor(conceptTxt.height / pix);
				
				tab_bar = new Sprite();
				tab_bar.graphics.beginFill(0xFFFFFF);
				tab_bar.graphics.drawRect(areaW - 8, 0,  6, areaH * (nowhave-avable) / avable);
				tab_bar.graphics.endFill();
				tab_bar.buttonMode = true;
				addChild(tab_bar);
				Rec = new Rectangle(0, 0, 0, areaH - tab_bar.height);
				
				tab_bar.addEventListener(MouseEvent.MOUSE_DOWN, tabDown);
			}} );
		}
		
		private function tabDown(e:MouseEvent) {
			tab_bar.startDrag(false, Rec );
			tab_bar.addEventListener(Event.ENTER_FRAME, dispatchNavScroll );
			parent.addEventListener(MouseEvent.MOUSE_UP, tabUP);
		}
		private function tabUP(e:MouseEvent) {
			tab_bar.stopDrag();
			tab_bar.removeEventListener(Event.ENTER_FRAME, dispatchNavScroll);
			parent.removeEventListener(MouseEvent.MOUSE_UP, tabUP);
		}
		
		private function dispatchNavScroll(e:Event) {
			var goAtY:int = Math.floor(tab_bar.y / (nowhave-avable));
			Tweener.addTween(conceptTxt, { y: -10 * goAtY, time:0.2, transition:"linear"});
		}
	}
}