使用套接字的c#委托不能很好地工作

我正在用c# (Winform)编写一个使用socket的聊天程序。这是我的一段源代码:
(Left和Mid函数与VB相同，将返回字符串)

服务器:

Socket Serv;
List<Socket> ClnSocket = new List<Socket>();
Socket socket;
Thread run;
private delegate void sDelegate(string sData, int socketIndex);
private void MainForm_Load(object sender, EventArgs e)
{
    Serv = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
    Serv.Bind(new IPEndPoint(IPAddress.Any, 9180));
    Serv.Listen(5);
    Thread accept = new Thread(this.Accept);
    accept.Start();
}
private void runChatting(object s)
{
    byte[] str;
    socket = s as Socket;
        while (true)
        {
            try
            {
                str = new byte[2048];
                socket.Receive(str);
                sDelegate sdelegate = new sDelegate(this.Receive);
                this.Invoke(sdelegate, Encoding.Default.GetString(str), ClnSocket.IndexOf(socket));
            }
            catch
            {
                ClnSocket.Remove(socket);
                return;
            }
        }
}
private void Receive(string sData, int socketIndex)
{
    this.textBox1.AppendText(sData);
    string TempData = Mid(sData, 11, sData.Length);
    string[] SpliteData = TempData.Split('#');
    if (Left(sData, 10) == "#musicadd#")
    {
        SendTo("#musicadd#" + SpliteData[1], socketIndex);
    }
    else
    {
        Send(sData);
    }
}
private void Send(string sData)
{
    int i;
    for (i = 0; i < ClnSocket.Count; i++)
    {
            ClnSocket[i].Send(Encoding.Default.GetBytes(sData));
    }
}
private void SendTo(string sData, int socketIndex)
{
        ClnSocket[socketIndex].Send(Encoding.Default.GetBytes(sData));
}
private void Accept()
{
    while (true)
    {
        ClnSocket.Add(Serv.Accept());
        run = new System.Threading.Thread(new System.Threading.ParameterizedThreadStart(this.runChatting));
        run.Start(ClnSocket[ClnSocket.Count - 1]);
    }
}

客户:

Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
Thread run;
public delegate void sDelegate(string sData);
public Form1()
{
    try
    {
        InitializeComponent();
        socket.Connect("localhost", 9180);
        run = new Thread(new ParameterizedThreadStart(Run));
        run.Start();
    }
    catch (Exception ex){
        MessageBox.Show(ex.ToString());
        System.Environment.Exit(0);
    }
}
private void Run(object s)
{
    byte[] str = new byte[2048];
    try
    {
        while (true)
        {
            socket.Receive(str);
            sDelegate sdelegate = new sDelegate(this.Receive);
            IntPtr x;
            if (!this.IsHandleCreated) x = this.Handle;
            this.Invoke(sdelegate, Encoding.Default.GetString(str));
        }
    }
    catch (Exception e)
    {
        MessageBox.Show("Connection Lost." + Environment.NewLine + e.ToString());
        Application.Exit();
    }
}
public void Receive(string sData)
{
    if (Left(sData, 10) == "#musicadd#")
    {
        this.MusicList.Items.Add(Mid(sData, 11, sData.Length));
    }
    Text_Board.AppendText(sData);
}
private void Text_Chat_KeyDown(object sender, KeyEventArgs e)
{
    if (e.KeyCode == Keys.Enter)
    {
        string str = this.Text_Chat.Text;
        this.Text_Chat.Text = "";
        Send(Encoding.Default.GetBytes(sData));
    }
}
public void Send(string sData)
{
    socket.Send(Encoding.Default.GetBytes(sData));
}
private void Button_Add_Click(object sender, EventArgs e)
{
    Send("#musicadd#" + "Test string");
}

聊天工作正常(Text_Chat_Keydown)，但当我调用Button_Add_Click时，客户端的ListBox永远不会改变，聊天不工作。

在这一点上我很困惑。有人能看出我做错了什么吗?

textBox1.AppendText(sData);
if (sData.Substring(0,10) == "#musicadd#")
    SendTo("#musicadd#", sData.Substring(10), socketIndex);
else
    Send(sData);