Asp.net MVC获取访问系统的客户端计算机的主机名和IP地址

string HostName = string.Empty; 
string ip = string.Empty;
string ipv4 = String.Empty;

if (!string.IsNullOrEmpty(System.Web.HttpContext.Current.Request.ServerVariables["HTTP_VIA"]))
     ip = Convert.ToString(System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"]);
if (string.IsNullOrEmpty(ip))
     ip = Request.UserHostAddress;

 // 利用 Dns.GetHostEntry 方法，由获取的 IPv6 位址反查 DNS 纪录，
 // 再逐一判断何者为 IPv4 协议，即可转为 IPv4 位址。
foreach (IPAddress ipAddr in Dns.GetHostEntry(ip).AddressList)
{
    if (ipAddr.AddressFamily.ToString() == "InterNetwork")
    {
        ipv4 = ipAddr.ToString();
    }
}

HostName = "主机名: " + Dns.GetHostEntry(ip).HostName + " IP: " + ipv4;