flash 容器滚动效果

import flash.display.MovieClip;
import flash.geom.Rectangle;
import fl.controls.UIScrollBar;
import fl.controls.ScrollBarDirection;
import fl.events.ScrollEvent;
var container:MovieClip=new MovieClip();
//container.addChild(create_mc());
//container.addChild(create_mc());
addChild(container);
var p_x:uint=0;
var p_y:uint=0;
var rect:Rectangle=new Rectangle(0,0,60,60);
container.scrollRect=rect;
for(var i:uint=0;i<36;i++){
if(i%3==0){
p_x=0;
if(i!=0){
p_y+=20;
}
}
var mc:MovieClip=create_mc();
mc.x=p_x;
mc.y=p_y;
p_x+=20;
container.addChild(mc);
}
//container.height=100;
var scroll_bar:UIScrollBar=new UIScrollBar();
scroll_bar.direction=ScrollBarDirection.VERTICAL;
scroll_bar.setScrollProperties(5,1,180);
scroll_bar.addEventListener(ScrollEvent.SCROLL,scroll_handle);
addChild(scroll_bar);
scroll_bar.y=150;
scroll_bar.x=150;

function scroll_handle(evt:ScrollEvent):void{
//trace(evt.target.scrollPosition);
var rect:Rectangle =container.scrollRect;
rect.y=Math.floor(evt.target.scrollPosition);
container.scrollRect=rect;
}
function create_mc():MovieClip{
var mc:MovieClip=new MovieClip();
mc.graphics.beginFill(0xFF0000,0.5);
mc.graphics.drawCircle(10,10,10);
mc.graphics.endFill();
return mc;
}