DisplayObjectをBase64文字列(png)に変換

convertBase64.as

/**
* DisplayObjectをBase64文字列(png)に変換.
* @param target  画像化したいDisplayObject
* @param w 幅
* @param h 高さ
*/
//import com.adobe.images.PNGEncoder;
//import mx.utils.Base64Encoder;

        private function convertBase64(target : DisplayObject, w : Number = NaN, h : Number = NaN) : String
        {
            w = (isNaN(w)) ? target.width : w;
            h = (isNaN(h)) ? target.height : h;

            var bmd : BitmapData = new BitmapData(w, h, true, 0x00ffffff);
            bmd.draw(target);
            var base64 : Base64Encoder = new Base64Encoder();
            base64.encodeBytes(PNGEncoder.encode(bmd));
            var str : String = base64.toString();
            bmd.dispose();
            var str3:String = "";
            var str2:String = str.toString();
            var len:uint = str2.length;
            for (var i:uint = 0; i < len; i++)
            {
                var sub:String = str2.substr(i, 1);
                if (sub == "\n")
                    continue;
                str3 += sub;
            }
            return str3;
        }