C#,在Client-Server伺服器架构中，server里ListenClient的str1值无法显示在Form1的textbox中？？

为什么下图1中显示的回传信息，在图2中窗体结构里，server的listenclient中的str1值，运行时无法回传显示在Textbox中？
在Form1中：
        private void button1_Click(object sender, EventArgs e)
        {
            try
        {          ………………
              
                textBox1.Text = "Server started at: " + serverIP.ToString() + ":" + Port;
                ListenClient lc = new ListenClient(serverSocket,str1);
                // 执行绪
                ThreadStart serverThreadStart = new ThreadStart(lc.ServerThreadProc);
textBox1.Text = textBox1.Text + " \r\n" + str1;
                Thread serverthread = new Thread(serverThreadStart);             
                serverthread.Start();             
            }
在ListenClient中：
namespace ServerSocket
{
  class ListenClient
  {
      public  string str1;
      private System.Net.Sockets.Socket serverSocket;
    private System.Net.Sockets.Socket clientSocket;
   
 public ListenClient(Socket serverSocket, String str1)
    {
      this.serverSocket = serverSocket;
      this.str1 = str1;
    }
    public void ServerThreadProc()
    {
      while (true)
      {
        try
        {
          clientSocket = serverSocket.Accept();
          IPEndPoint serverInfo = (IPEndPoint)serverSocket.LocalEndPoint;
          IPEndPoint clientInfo = (IPEndPoint)clientSocket.RemoteEndPoint;
       
     str1= "Server: " + serverInfo.Address.ToString() + ":" + serverInfo.Port.ToString() + "\r\n";
        str1+="Client: " + clientInfo.Address.ToString() + ":" + clientInfo.Port.ToString()+"\r\n";
         
         …………
        } --------------------编程问答-------------------- 把你的代码修改如下试试：
                // 执行绪
                ThreadStart serverThreadStart = new ThreadStart(lc.ServerThreadProc);
                Thread serverthread = new Thread(serverThreadStart);             
                serverthread.Start();    
                 textBox1.Text = textBox1.Text + " \r\n" + lc.str1;
  --------------------编程问答-------------------- 试过了，窗体的Textbox里还是无法显示相关的内容~

补充：.NET技术 ,  C#