C#中通过IP获取MAC地址，获取本机IP和MAC地址

protected void Page_Load(object sender, EventArgs e)
    {
        Response.Write("MAC地址为："+GetMACAddress()+"IP地址为："+GetAddress()+"<br>");
        Response.Write("mac是:" + GetMACByIP("192.168.100.3")+"<br>");
        Response.Write("mac是:" + GetMACByIP(GetAddress()));
    }

    //获取本机MAC地址
    public static string GetMACAddress()
    {
        string MoAddress = "";
        ManagementClass mc = new ManagementClass("Win32_NetworkAdapterConfiguration");
        ManagementObjectCollection moc = mc.GetInstances();
        foreach (ManagementObject mo in moc)
        {
            if ((bool)mo["IPEnabled"] == true)
                MoAddress = mo["MacAddress"].ToString();
            mo.Dispose();
        }
        return MoAddress;
    }

注意：1.使用程序集system.management
        2.使用命名空间system.management
          你必须把system.management这个dll引用进你的工程中来。
          不然的话找不到这个dll，也找不到引用的命名空间和类。
    //获取本机IP地址
    public static string GetAddress()
    {
        string strHostName = Dns.GetHostName(); //得到本机的主机名
        IPHostEntry ipEntry = Dns.GetHostByName(strHostName); //取得本机IP
        return ipEntry.AddressList[0].ToString();  
    }

  [DllImport("Iphlpapi.dll")]
  private static extern int SendARP(Int32 dest,Int32 host,byte[] mac,ref Int32 length);
  [DllImport("Ws2_32.dll")] 
  private static extern Int32 inet_addr(string ip);

  /// <summary>
  /// 根据ip得到网卡mac地址
  /// </summary>
  /// <param name="ip">给出的ip地址</param>
  /// <returns>对应ip的网卡mac地址</returns>
  public static string GetMACByIP(string ip) 
  { 
   try 
   { 
    byte[] aa=new byte[6];

    Int32 ldest= inet_addr(ip); //目的地的ip

    Int64 macinfo = new Int64(); 
    Int32 len = 6; 
    int res = SendARP(ldest,0, aa, ref len);

    return BitConverter.ToString( aa, 0, 6 );;
   } 
   catch(Exception err) 
   { 
    throw err; 
   }