[转]用C#获取局域网内所有机器

原理其实很简单，在cmd.exe下面ping一下几台机，然后用arp -a命令查看一下，这种方式比开多线程去循环扫描的方式来的简单而有效。

//首先来个循环ping一下那个网段的主机。

//其次用以下的函数去获取所有的局域网内有响应的ip地址列表

public static ArrayList GetAllLocalMachines()

{

Process p = new Process();

p.StartInfo.FileName = "cmd.exe";

p.StartInfo.UseShellExecute = false;

p.StartInfo.RedirectStandardInput = true;

p.StartInfo.RedirectStandardOutput = true;

p.StartInfo.RedirectStandardError = true;

p.StartInfo.CreateNoWindow = true;

p.Start();

p.StandardInput.WriteLine("arp -a");

p.StandardInput.WriteLine("exit");

ArrayList list = new ArrayList();

StreamReader reader = p.StandardOutput;

string IPHead = Dns.GetHostByName(Dns.GetHostName()).AddressList[0].ToString().Substring(0, 3);

for (string line = reader.ReadLine(); line != null; line = reader.ReadLine())

{

line = line.Trim();

if (line.StartsWith(IPHead) && (line.IndexOf("dynamic") != -1))

{

string IP = line.Substring(0, 15).Trim();

string Mac = line.Substring(line.IndexOf("-") - 2, 0x11).Trim();

LocalMachine localMachine = new LocalMachine();

localMachine.MachineIP = IP;

localMachine.MachineMAC = Mac;

localMachine.MachineName = "";

list.Add(localMachine);

}

}

return list;

}