本人新手初学C#网络编程，发现了一个很奇怪的问题，就是在while循环中下断，居然不断下来，只有当收到数据时才会断下来

private void AccepMessage()
        {
            NetworkStream netStream = new NetworkStream(socket);
            while (true)
            {
                try
                {
                    byte[] datasize = new byte[4];
                    netStream.Read(datasize, 0, 4);//我在此处下断，不会断下来，只有当收到数据时才会断下来
                    int size = System.BitConverter.ToInt32(datasize, 0);
                    Byte[] message = new byte[size];
                    int dataleft = size;
                    int start = 0;
                    while (dataleft > 0)
                    {
                        int recv = netStream.Read(message, start, dataleft);
                        start += recv;
                        dataleft -= recv;
                    }
                    this.rchTxtBoxReceive.Text = System.Text.Encoding.Unicode.GetString(message);
                }
                catch
                {
                    break;
                }
            }
        }

 private void btnRequest_Click(object sender, EventArgs e)
        {            
            thread = new Thread(new ThreadStart(AccepMessage));
            thread.Start();
        }

请问这是为什么?

[培训]内核驱动高级班，冲击BAT一流互联网大厂工作，每周日13:00-18:00直播授课