获取用户的IP地址

Question

如何获取当前访客的IP地址？

Answer 1

编辑:还发现了关于IP相关的HTTP头一个有趣的问题在这里.

Edit2:正如我在上面提供的评论和链接中所提到的,HTTP_X_FORWARDED_FOR标题可能包含多个以逗号分隔的IP地址.我没有遇到这种情况,但想要对我的答案进行一些修改是必要的.

我使用此代码获取IP地址(IPAddress.None如果由于某种原因失败,则返回值):

    /// <summary>
    /// Gets the IP address of the request.
    /// <remarks>
    /// This method is more useful than built in because in some cases it may show real user IP address even under proxy.
    /// <summary>
    /// Gets the IP address of the request.
    /// <remarks>
    /// This method is more useful than built in because in some cases it may show real user IP address even under proxy.
    /// The <see cref="System.Net.IPAddress.None" /> value will be returned if getting is failed.
    /// </remarks>
    /// </summary>
    /// <param name="request">The HTTP request object.</param>
    /// <returns></returns>
    public static IPAddress GetIp(this HttpRequest request)
    {
        string ipString;
        if (string.IsNullOrEmpty(request.ServerVariables["HTTP_X_FORWARDED_FOR"]))
        {
            ipString = request.ServerVariables["REMOTE_ADDR"];
        }
        else
        {
            ipString = request.ServerVariables["HTTP_X_FORWARDED_FOR"].Split(",".ToCharArray(), StringSplitOptions.RemoveEmptyEntries)
                .FirstOrDefault();
        }

        IPAddress result;
        if (!IPAddress.TryParse(ipString, out result))
        {
            result = IPAddress.None;
        }

        return result;
    }

Answer 2

HttpContext.Current.Request.UserHostAddress;

要么

HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];

要么

HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];