C# 获取 mp3文件信息【包括：文件大小、歌曲长度、歌手、专辑】

// http://bbs.csdn.net/topics/390392612

https://download.csdn.net/download/u013087481/10952812

 public struct Mp3Info
    {
        public string identify;//TAG，三个字节     
        public string Title;//歌曲名,30个字节     
        public string Artist;//歌手名,30个字节     
        public string Album;//所属唱片,30个字节      
        public string Year;//年,4个字符     
        public string Comment;//注释,28个字节      
        public char reserved1;//保留位，一个字节        
        public char reserved2;//保留位，一个字节        
        public char reserved3;//保留位，一个字节     
    }     
    /// <summary>
    /// mp3类
    /// </summary>
    public class clsMP3
    {
        public void fLogSave(Page _sender, Hashtable _htUser)
        {
            
        }
        //所以，我们只要把MP3文件的最后128个字节分段读出来并保存到该结构里就可以了。函数定义如下：     
        private 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;
        }
        //再对上面返回的字节数组分段取出，并保存到Mp3Info结构中返回:   
        private Mp3Info getMp3Info(byte[] Info)
        {
            Mp3Info mp3Info = new Mp3Info();
            string str = null;
            int i;
            int position = 0;//循环的起始值     
            int currentIndex = 0;//Info的当前索引值     
            //获取TAG标识(数组前3个)     
            for (i = currentIndex; i < currentIndex + 3; i++)
            {
                str = str + (char)Info[i];
                position++;
            }
            currentIndex = position;
            mp3Info.identify = str;
           //获取歌名（数组3-32）     
            str = null;
            byte[] bytTitle = new byte[30];//将歌名部分读到一个单独的数组中     
            int j = 0;
            for (i = currentIndex; i < currentIndex + 30; i++)
            {
                bytTitle[j] = Info[i];
                position++;
                j++;
            }
            currentIndex = position;
            mp3Info.Title = this.byteToString(bytTitle);
           //获取歌手名（数组33-62）     
            str = null;
            j = 0;
            byte[] bytArtist = new byte[30];//将歌手名部分读到一个单独的数组中     
            for (i = currentIndex; i < currentIndex + 30; i++)
            {
                bytArtist[j] = Info[i];
                position++;
                j++;
            }
            currentIndex = position;
            mp3Info.Artist = this.byteToString(bytArtist);
            //获取唱片名（数组63-92）     
            str = null;
            j = 0;
            byte[] bytAlbum = new byte[30];//将唱片名部分读到一个单独的数组中     
            for (i = currentIndex; i < currentIndex + 30; i++)
            {
                bytAlbum[j] = Info[i];
                position++;
                j++;
            }
            currentIndex = position;
            mp3Info.Album = this.byteToString(bytAlbum);
            //获取年 （数组93-96）    
            str = null;
            j = 0;
            byte[] bytYear = new byte[4];//将年部分读到一个单独的数组中     
            for (i = currentIndex; i < currentIndex + 4; i++)
            {
                bytYear[j] = Info[i];
                position++;
                j++;
            }
            currentIndex = position;
            mp3Info.Year = this.byteToString(bytYear);
            //获取注释（数组97-124）     
            str = null;
            j = 0;
            byte[] bytComment = new byte[28];//将注释部分读到一个单独的数组中     
            for (i = currentIndex; i < currentIndex + 25; i++)
            {
                bytComment[j] = Info[i];
                position++;
                j++;
            }
            currentIndex = position;
            mp3Info.Comment = this.byteToString(bytComment);
            //以下获取保留位（数组125-127）     
            mp3Info.reserved1 = (char)Info[++position];
            mp3Info.reserved2 = (char)Info[++position];
            mp3Info.reserved3 = (char)Info[++position];
            return mp3Info;
        }
        //上面程序用到下面的方法：     
        ///   <summary>     
        ///   将字节数组转换成字符串    
        ///   </summary>     
        ///   <param   name   =   "b">字节数组</param>     
        ///   <returns>返回转换后的字符串</returns>     
        private string byteToString(byte[] b)
        {
            Encoding enc = Encoding.GetEncoding("GB2312");
            string str = enc.GetString(b);
            str = str.Substring(0, str.IndexOf(‘\0‘) >= 0 ? str.IndexOf(‘\0‘) : str.Length);//去掉无用字符     
            return str;
        } 
    }