private async void server_start_button_Click(object sender, EventArgs e)
        {
            network_status_lab.Text = "クライアント待機中";
            //tcp.listen();
            int port = int.Parse(port_box.Text);

            server_start_button.Enabled = false;

            if (tcp == null)
            {
                tcp = new tcp_conection("0.0.0.0", port);
            }

            await Task.Run(() => listen());
        }
        private async void server_start_button_Click(object sender, EventArgs e)
        {
            network_status_lab.Text = "クライアント待機中";
            //tcp.listen();
            int port = int.Parse(port_box.Text);
            server_start_button.Enabled = false;

            if(tcp == null)
            {
                tcp = new tcp_conection("0.0.0.0",port);
            }

            await Task.Run(() => listen());
        }