Socket 和Thread.Abort问题

[sheng5521627]

        TcpListener lis = null;
        private void button1_Click(object sender, EventArgs e)
        {
            lis = new TcpListener(2100);
            lis.Start();
            System.Threading.Thread t = new System.Threading.Thread(new System.Threading.ThreadStart(f));
            t.Start();
            //t.Abort();
        }
        private void f()
        {
            lis.AcceptSocket();
        }
        private void button2_Click(object sender, EventArgs e)
        {
            lis.Stop();            
        }

我本想当点击button2时，关闭lis对象
但窗体也关闭了
而我添加t.Abort后，窗体不会关闭了
我想知道窗体和子线程之间存在什么样的联系

[sprc_lcl]

        TcpListener lis = null;
        Thread t;
        private void button1_Click(object sender, EventArgs e)
        {
            lis = new TcpListener(2100);
            lis.Start();
            t = new System.Threading.Thread(new System.Threading.ThreadStart(f));
            t.IsBackground = true;
            t.Start();
        }
        private void f()
        {
            while (true)
            {
                Socket s = lis.AcceptSocket();
                //do s
            }
        }
        private void button2_Click(object sender, EventArgs e)
        {
            try
            {
                t.Abort();
            }
            catch
            { }
            lis.Stop();