[ActionScript 3.0] 通过BitmapData将对象保存成jpg图片

此方法需要用到JPGEncoder.as和BitString.as这两个类，是将BitmapData对象转换成ByteArray，然后通过FileStream把此ByteArray写入到文件保存成jpg图片,因为用到File相关类，故需要用air播放器发布flash，在此提供两个下载JPGEncoder.as和BitString.as类的地址，

CSDN：http://download.csdn.net/source/3205224

Adobe官方的CoreLib下载: http://code.google.com/p/as3corelib/ 使用其中的:com.adobe.images.JPEGEncoder

以下是一个简单例子，SaveToJPEG .as 类 可直接作为文档类

package 
{
    import JPEGEncoder.JPGEncoder;
    import flash.display.Bitmap;
    import flash.display.BitmapData;
    import flash.display.Loader;
    import flash.display.MovieClip;
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.MouseEvent;
    import flash.filesystem.File;
    import flash.filesystem.FileMode;
    import flash.filesystem.FileStream;
    import flash.geom.Rectangle;
    import flash.net.URLRequest;
    import flash.text.TextField;
    import flash.text.TextFieldAutoSize;
    import flash.utils.ByteArray;

    /**
      * ...
      * @author Frost.Yen
      */
    public class SaveToJPEG extends Sprite
    {
        var ldr:Loader = new Loader();
        var rect:Rectangle;
        var bytearr:ByteArray;
        public function SaveToJPEG():void
        {
            init();
        }

        private function init():void
        {
            var btnMC:MovieClip = new MovieClip();
            btnMC.graphics.beginFill(0xcccccc);
            btnMC.graphics.drawRoundRect(0, 0, 100, 40, 10, 10);
            btnMC.graphics.endFill();
            btnMC.x = 630;
            btnMC.y = 50;
            btnMC.buttonMode = true;
            btnMC.addEventListener(MouseEvent.CLICK, onClick);
            this.addChild(btnMC);

            var txt:TextField = new TextField();
            txt.autoSize = TextFieldAutoSize.LEFT;
            txt.selectable = false;
            txt.mouseEnabled = false;
            txt.text = "点击保存此图片";
            txt.x = (btnMC.width - txt.width) / 2;
            txt.y = (btnMC.height - txt.height) / 2;
            btnMC.addChild(txt);

            ldr.load(new URLRequest("http://hiphotos.baidu.com/frostyen/pic/item/7e49d8b53f6b48ffd9335aa2.jpg"));
            ldr.contentLoaderInfo.addEventListener(Event.COMPLETE, onComplete);
        }

        private function onClick(e:MouseEvent):void
        {
            if (bytearr != null)
            {
                var file:File = new File();
                file.browseForDirectory("保存");
                file.addEventListener(Event.SELECT, onSelectPath);
            }
        }

        private function onSelectPath(e:Event):void
        {
            var file:File = (e.target as File).resolvePath("松竹梅副本.jpg");
            var filestream:FileStream = new FileStream();
            filestream.open(file, FileMode.WRITE);
            filestream.writeBytes(bytearr);
        }

        private function onComplete(e:Event):void
        {
            this.addChild(ldr);
            rect = ldr.getRect(ldr);

            var bmpd:BitmapData = new BitmapData(rect.width,rect.height);
            bmpd.draw(ldr);
            var jpg:JPGEncoder = new JPGEncoder();
            bytearr = jpg.encode(bmpd) as ByteArray;
        }
    }
}