新手求教。解决办法

新手求教。。。。
//MP3Info.cs

C# code

using System;using System.Collections.Generic;using System.Text;namespace WindowsApplication1{    public class MP3Info    {        private int tagLen = 128;        private string mp3Tag = string.Empty;        private string title = string.Empty;        public string MP3Tag        {            get { return mp3Tag; }            set { mp3Tag = value; }        }        public string Title        {            get { return title; }            set { title = value; }        }    }}

C# code

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Text;using System.Windows.Forms;using System.IO;namespace WindowsApplication1{    public partial class Form1 : Form    {       }        MP3Tag="";   //这句为什么不能通过呢？}

C# code

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Text;using System.Windows.Forms;using System.IO;namespace WindowsApplication1{    public partial class Form1 : Form    {           public Form1()      {     MP3Info mp3=new MP3Info();     mp3.MP3Tag="";     }       }      }