如何扫描本地局域网？

Question

我在C＃中创建了一个扫描局域网中所有PC的程序，然后打印出IP列表和计算机名称。此处的代码我在YouTube上覆盖了某人。但是当我尝试扫描时，它总是返回错误：

Additional information: An exception occurred during a Ping request.

我尝试在LAN网络中的所有PC中关闭防火墙，但仍然存在此问题。我花了很多时间才弄明白，但仍然不知道下一步该做什么。

    Thread myThread = null;

    public void scan(string subnet)
    {
        Ping myPing;
        PingReply reply;
        IPAddress addr;
        IPHostEntry host;

        for (int i = 1; i < 255; i++)
        {
            string subnetn = "." + i.ToString();
            myPing = new Ping();
            reply = myPing.Send(subnet + subnetn);

            if (reply.Status == IPStatus.Success)
            {
                try
                {
                    addr = IPAddress.Parse(subnet + subnetn);
                    host = Dns.GetHostEntry(addr);

                    txtHosts.AppendText(subnet + subnetn + host.HostName.ToString() + "Up");


                }
                catch
                {

                }
            }
        }
    }



    private void cmdScan_Click(object sender, EventArgs e)
    {
        myThread = new Thread(() => scan(txtIP.Text));
        myThread.Start();

        if (myThread.IsAlive)
        {
            cmdStop.Enabled = true;
            cmdScan.Enabled = false;
            txtIP.Enabled = false;

        }
    }

    private void cmdStop_Click(object sender, EventArgs e)
    {
        myThread.Suspend();
        cmdScan.Enabled = true;
        cmdStop.Enabled = false;
        txtIP.Enabled = true;
    }
}