获取客户端相关信息

//添加组件System.Management 
using   System.Management; 
using   System.Runtime.InteropServices; 

[DllImport( "Iphlpapi.dll ")] 
        private   static   extern   int   SendARP(Int32   dest,   Int32   host,   ref   Int64   mac,   ref   Int32   length); 
        [DllImport( "Ws2_32.dll ")] 
        private   static   extern   Int32   inet_addr(string   ip); 


protected   void   Page_Load(object   sender,   EventArgs   e) 
        { 
                try 
                { 
                        string   userip   =   Request.UserHostAddress;   
                        Int32   ldest   =   inet_addr(userip);       //目的地的ip           
                        Int32   lhost   =   inet_addr( " ");       //本地服务器的ip           
                        Int64   macinfo   =   new   Int64(); 
                        Int32   len   =   6; 
                        int   res   =   SendARP(ldest,   0,   ref       macinfo,   ref       len); 
                        string   mac_src   =   macinfo.ToString( "X "); 
                        if   (mac_src   ==   "0 ") 
                        { 
                                if   (userip   ==   "127.0.0.1 ") 
                                        userinfo.Text   =   "正在访问Localhost! "; 
                                else 
                                        userinfo.Text   =   "欢迎来自IP为 "   +   userip   +   "的朋友！ "; 
                                return; 
                        } 
                        while   (mac_src.Length   <   12) 
                        { 
                                mac_src   =   mac_src.Insert(0,   "0 "); 
                        } 
                        string   mac_dest   =   " "; 
                        for   (int   i   =   0;   i   <   11;   i++) 
                        { 
                                if   (0   ==   (i   %   2)) 
                                        mac_dest   =   mac_dest.Insert(0,   mac_src.Substring(i,   2)); 
                        } 
                        userinfo.Text   =   "欢迎来自IP为 "   +   userip   +   ",MAC地址为 "   +   mac_dest   +   "的朋友！ "; 
                } 
                catch   (Exception   err) 
                { 
                        Response.Write(err.Message); 
                }     
        }