Flex中字符编码识别

关键：读取开头2个字节，utf-8前3个字节是ef bb bf ，unicode前2个字节是fffe或者feff，ansi则没有这些标志！
搞了一天，终于可以识别各种格式的LRC歌词了。放出部分代码

??? var strCode:int= this.stream.readByte();
??????????????? ??? ??? var str:String = new String();
??????????????????????? trace(strCode);
??????? ??? ??? ??? ??? switch(strCode)
??????? ??? ??? ??? ??? {
??? ??????? ??? ??? ??? ??? case -1:
??? ??? ??????? ??? ??? ??? ??? //第一个字符为-1则是unicode
??? ??? ??????? ??? ??? ??? ??? this.charset="unicode";
??? ??? ??????? ??? ??? ??? ??? this.stream.readByte();
??? ??? ??????? ??? ??? ??? ??? str = this.stream.readMultiByte(this.stream.bytesAvailable,this.charset);
??? ??? ??????? ??? ??? ??? ??? break;
??? ??? ??????? ??? ??? ??? case -17:
??? ??? ??? ??????? ??? ??? ??? //第一个字符为-17则是utf-8
??? ??? ??? ??????? ??? ??? ??? this.charset="utf-8";
??? ??? ??? ??????? ??? ??? ??? this.stream.readByte();
??? ??? ??? ??????? ??? ??? ????
??? ??? ??? ??????? ??? ??? ??? str = this.stream.readMultiByte(this.stream.bytesAvailable,51); font-family:Arial; font-size:14px; line-height:26px; text-align:left">??? ??? ??? ??????? ??? ??? ??? break;
??? ??? ??? ??????? ??? ??? default:
??? ??? ??? ??????? ??? ??? ??? this.charset="ansi";
??? ??? ??? ??????? ??? ??? ??? str = String.fromCharCode(strCode);
??? ??? ??? ??????? ??? ??? ??? str? += this.stream.readMultiByte(this.stream.bytesAvailable,51); font-family:Arial; font-size:14px; line-height:26px; text-align:left">??????? ??? ??? ??? ??? }
??????? ??? ??? ??? ??? trace(str);