1. getDefinistionByName as Class

import flash.utils.getDefinitionByName;
var className:Class = getDefinistionByName( StringName ) as Class;
var foo:Sprite = new className();

source

2. BitmapDataUnlimited

import com.formatlos.as3.lib.display.BitmapDataUnlimited;
import com.formatlos.as3.lib.display.events.BitmapDataUnlimitedEvent;

var bdu:BitmapDataUnlimited = new BitmapDataUnlimited();
bdu.addEventListener(BitmapDataUnlimitedEvent.COMPLETE, onBmpReady);
bdu.create(5000, 5000, true);

var hugeBmp : BitmapData;

function onBmpReady(event : BitmapDataUnlimitedEvent) : void
{
hugeBmp = bdu.bitmapData;
trace("BitmapData: w=" + hugeBmp.width + " h=" + hugeBmp.height);
}

e.g. a BitmapData with 12000 x 12000 px needs more than 1GB.

3、Photoshop技巧：提高截屏图片打印的分辨率 - PS普通截屏图片到300dpi的分辨率