（转载）BitmapData与ByteArray的转换

【转载】BitmapData与ByteArray的转换

2010-05-14 09:39:39| 分类： actionscript 3|字号订阅

有用，转过来，做参考

package com.klstudio.images {

    import flash.display.BitmapData;
    import flash.geom.Rectangle;
    import flash.utils.ByteArray;

    import com.klstudio.util.Base64;

    public class BitmapBytes {

        public static function encodeByteArray(data:BitmapData):ByteArray{
            if(data == null){
                throw new Error("data参数不能为空!");
            }
            var bytes:ByteArray = data.getPixels(data.rect);
            bytes.writeShort(data.width);
            bytes.writeShort(data.height);
            bytes.writeBoolean(data.transparent);
            bytes.compress();
            return bytes;
        }
        public static function encodeBase64(data:BitmapData):String{
            return Base64.encodeByteArray(encodeByteArray(data));
        }

        public static function decodeByteArray(bytes:ByteArray):BitmapData{
            if(bytes == null){
                throw new Error("bytes参数不能为空!");
            }
            bytes.uncompress();
            if(bytes.length < 6){
                throw new Error("bytes参数为无效值!");
            }
            bytes.position = bytes.length - 1;
            var transparent:Boolean = bytes.readBoolean();
            bytes.position = bytes.length - 3;
            var height:int = bytes.readShort();
            bytes.position = bytes.length - 5;
            var int = bytes.readShort();
            bytes.position = 0;
            var datas:ByteArray = new ByteArray();
            bytes.readBytes(datas,0,bytes.length - 5);
            var bmp:BitmapData = new BitmapData(width,height,transparent,0);
            bmp.setPixels(new Rectangle(0,0,width,height),datas);
            return bmp;
        }

        public static function decodeBase64(data:String):BitmapData{
            return decodeByteArray(Base64.decodeToByteArray(data));
        }

        public function BitmapBytes() {
            throw new Error("BitmapBytes类只是一个静态类!");
        }

    }

}