ASP.NET擷取用戶端IP/使用者名稱等資訊

1. 在ASP.NET中專用屬性：
擷取伺服器電腦名：Page.Server.ManchineName
擷取使用者資訊：Page.User
擷取用戶端電腦名：Page.Request.UserHostName
擷取用戶端電腦IP：Page.Request.UserHostAddress

2. 在網路編程中的通用方法：
擷取當前電腦名：static System.Net.Dns.GetHostName()
根據電腦名取出全部IP地址：static System.Net.Dns.Resolve(電腦名).AddressList
也可根據IP地址取出電腦名：static System.Net.Dns.Resolve(IP地址).HostName

3. 系統內容類的通用屬性：
當前電腦名：static System.Environment.MachineName
當前電腦所屬網域：static System.Environment.UserDomainName
當前電腦使用者：static System.Environment.UserName  

4. if(Request.ServerVariables["HTTP_VIA"]!=null){  string     user_IP=Request.ServerVariables["HTTP_X_FORWARDED_FOR"].ToString();    
            }else{    
              string     user_IP=Request.ServerVariables["REMOTE_ADDR"].ToString();    
          }    
5.<%=Request.UserHostAddress%>

6.擷取用戶端IP:

private string GetClientIP()
  {
   string result = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
   if (null == result || result == String.Empty)
   {
    result = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
   }

   if (null == result || result == String.Empty)
   {
    result = HttpContext.Current.Request.UserHostAddress;
   }
   return result;
  }

擷取MAC地址:

[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);

  private void Page_Load(object sender, System.EventArgs e)
  {
   // 在此處放置使用者代碼以初始化頁面
   try
   {
    string userip=Request.UserHostAddress;
    string strClientIP = Request.UserHostAddress.ToString().Trim();
    Int32 ldest = inet_addr(strClientIP); //目的地的ip
    Int32 lhost = inet_addr("");   //本機伺服器的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")
      Response.Write ("正在訪問Localhost!");
     else
      Response.Write ("歡迎來自IP為" + userip + "的朋友！" + "<br>");
     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))
     {
      if ( i == 10 )
      {
       mac_dest = mac_dest.Insert(0,mac_src.Substring(i,2));
      }
      else
      {
       mac_dest ="-" + mac_dest.Insert(0,mac_src.Substring(i,2));
      }
     }
    }

    Response.Write ("歡迎來自IP為"+userip+ "<br>" + ",MAC地址為"+mac_dest+"的朋友！"

     +   "<br>");
   }
   catch(Exception err)
   {
    Response.Write(err.Message);
   }
  }