单for循环
for(var i:int=0;i<20;i++)
{
var sp:Sprite=new Sprite()
var bmd:BitmapData=new BitmapData(50,50,false,Math.random()*0xffffff);
var bmp:Bitmap=new Bitmap(bmd);
sp.addChild(bmp);
addChild(sp)
sp.x=(i%num)*50;
sp.y=int(i/num)*50;
sp.name=i+''
}