C#讀取媒體資訊

using System;  
using System.Collections.Generic;  
using System.Text;  
using System.IO;  
namespace Foxer_Player_1._1  
{  
    public struct Mp3Info  
    {  
        public string identify;     //TAG，三個位元組   
        public string Title;        //歌曲名,30個位元組   
        public string Artist;       //歌手名,30個位元組   
        public string Album;        //所屬唱片,30個位元組   
        public string Year;         //年,4個字元   
        public string Comment;      //注釋,28個位元組   
        public char reserved1;      //保留位，一個位元組   
        public char reserved2;      //保留位，一個位元組   
        public char reserved3;      //保留位，一個位元組   
    }  
    /// <summary>  
    /// Mp3檔案資訊類  
    /// </summary>  
    public class Mp3FileInfo  
    {  
        Mp3Info info;  
        /// <summary>  
        /// 建構函式,輸入檔案名稱即得到資訊  
        /// </summary>  
        /// <param name="mp3FilePos"></param>  
        public Mp3FileInfo(String mp3FilePos)  
        {  
            info = getMp3Info(getLast128(mp3FilePos));  
        }  
        /// <summary>  
        /// 擷取整理後的Mp3檔案名稱,這裡以標題和藝術家名定檔案名稱  
        /// </summary>  
        /// <returns></returns>  
        public String GetOriginalName()  
        {  
            return formatString(info.Title.Trim()) + "-" + formatString(info.Artist.Trim());  
        }  
        /// <summary>  
        /// 去除\0字元  
        /// </summary>  
        /// <param name="str"></param>  
        /// <returns></returns>  
        private static String formatString(String str)  
        {  
            return str.Replace("\0", "");  
        }  
        /// <summary>   
        /// 擷取MP3檔案最後128個位元組   
        /// </summary>   
        /// <param name="FileName">檔案名稱</param>   
        /// <returns>返回位元組數組</returns>   
        public static byte[] getLast128(string FileName)  
        {  
            FileStream fs = new FileStream(FileName, FileMode.Open, FileAccess.Read);  
            Stream stream = fs;  
            stream.Seek(-128, SeekOrigin.End);  
            const int seekPos = 128;  
            int rl = 0;  
            byte[] Info = new byte[seekPos];  
            rl = stream.Read(Info, 0, seekPos);  
            fs.Close();  
            stream.Close();  
            return Info;  
        }  
        /// <summary>   
        /// 擷取MP3歌曲的相關資訊   
        /// </summary>   
        /// <param name = "Info">從MP3檔案中截取的二進位資訊</param>   
        /// <returns>返回一個Mp3Info結構</returns>   
        public static Mp3Info getMp3Info(byte[] Info)  
        {  
            Mp3Info mp3Info = new Mp3Info();  
            string str = null;  
            int i;  
            int position = 0;//迴圈的起始值   
            int currentIndex = 0;//Info的當前索引值  
            //擷取TAG標識  
            for (i = currentIndex; i < currentIndex + 3; i++)  
            {  
                str = str + (char)Info[i];  
                position++;  
            }  
            currentIndex = position;  
            mp3Info.identify = str;  
 
            //擷取歌名   
            str = null;  
            byte[] bytTitle = new byte[30];//將歌名部分讀到一個單獨的數組中   
            int j = 0;  
            for (i = currentIndex; i < currentIndex + 30; i++)  
            {  
                bytTitle[j] = Info[i];  
                position++;  
                j++;  
            }  
            currentIndex = position;  
            mp3Info.Title = Foxer_Player_1._1.Mp3FileInfo.byteToString(bytTitle);  
 
            //擷取歌手名  
            str = null;  
            j = 0;  
            byte[] bytArtist = new byte[30];//將歌手名部分讀到一個單獨的數組中  
            for (i = currentIndex; i < currentIndex + 30; i++)  
            {  
                bytArtist[j] = Info[i];  
                position++;  
                j++;  
            }  
            currentIndex = position;  
            mp3Info.Artist = Foxer_Player_1._1.Mp3FileInfo.byteToString(bytArtist);  
 
            //擷取唱片名   
            str = null;  
            j = 0;  
            byte[] bytAlbum = new byte[30];//將唱片名部分讀到一個單獨的數組中  
            for (i = currentIndex; i < currentIndex + 30; i++)  
            {  
                bytAlbum[j] = Info[i];  
                position++;  
                j++;  
            }  
            currentIndex = position;  
            mp3Info.Album = Foxer_Player_1._1.Mp3FileInfo.byteToString(bytAlbum);  
 
            //擷取年   
            str = null;  
            j = 0;  
            byte[] bytYear = new byte[4];//將年部分讀到一個單獨的數組中  
            for (i = currentIndex; i < currentIndex + 4; i++)  
            {  
                bytYear[j] = Info[i];  
                position++;  
                j++;  
            }  
            currentIndex = position;  
            mp3Info.Year = Foxer_Player_1._1.Mp3FileInfo.byteToString(bytYear);  
            //擷取注釋  
            str = null;  
            j = 0;  
            byte[] bytComment = new byte[28];//將注釋部分讀到一個單獨的數組中  
            for (i = currentIndex; i < currentIndex + 25; i++)  
            {  
                bytComment[j] = Info[i];  
                position++;  
                j++;  
            }  
            currentIndex = position;  
            mp3Info.Comment = Foxer_Player_1._1.Mp3FileInfo.byteToString(bytComment);  
 
            //以下擷取保留位   
            mp3Info.reserved1 = (char)Info[++position];  
            mp3Info.reserved2 = (char)Info[++position];  
            mp3Info.reserved3 = (char)Info[++position];  
            return mp3Info;  
        }  
        /// <summary>  
        /// 將位元組數群組轉換成字串   
        /// </summary>   
        /// <param name = "b">位元組數組</param>   
        /// <returns>返迴轉換後的字串</returns>  
        public static string byteToString(byte[] b)  
        {  
            Encoding enc = Encoding.GetEncoding("GB2312");  
            string str = enc.GetString(b);  
            str = str.Substring(0, str.IndexOf("#CONTENT#") >= 0 ? str.IndexOf("#CONTENT#") : str.Length);//去掉無用字元               
            return str;  
        }  
    } 
}