得到當前頁面客戶端的IP

/// <summary>得到當前頁面客戶端的IP
///
/// </summary>
/// <returns>當前頁面客戶端的IP</returns>
public static string GetIP()
{
string result = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
if (string.IsNullOrEmpty(result))
result = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];

if (string.IsNullOrEmpty(result))
result = HttpContext.Current.Request.UserHostAddress;

if (string.IsNullOrEmpty(result) || !IsIP(result))
return "127.0.0.1";

return result;
}