C# 获取本机对外的IP

Question

如何在Winform中获取出本机对外的Ip，不是内网的Ip，请各位看看怎么弄呢

Answer 1

自己没法直接获得，只能通过访问某个站点再取得IP。写一个简单的网站，只有1个页面，写2句简单代码：<%
    Response.Write(Request.ServerVariables("REMOTE_ADDR"))
    Response.End
%>保存成 ip.asp然后用iis建一个网站，启动页面设成 ip.asp ，然后你通过外网访问时就会显示出你的外访IP。在winform程序里写上如下代码：
public string GetIP()
{
    WebClient web = new WebClient();
    string hostip = web.DownloadString("http://yourwwww.com.cn/ip.asp");
    return hostip;
}

Answer 2

/// <summary>
        /// 获取用户IP地址
        /// </summary>
        /// <returns></returns>
        public static string GetIPAddress()
        {            string user_IP = string.Empty;
            if (System.Web.HttpContext.Current.Request.ServerVariables["HTTP_VIA"] != null)
            {
                if (System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"] != null)
                {
                    user_IP = System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"].ToString();
                }
                else
                {
                    user_IP = System.Web.HttpContext.Current.Request.UserHostAddress;
                }
            }
            else
            {
                user_IP = System.Web.HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"].ToString();
            }
            return user_IP;
        }

Answer 3

/// <summary>
        /// 获取用户IP地址
        /// </summary>
        /// <returns></returns>
        public static string GetIPAddress()
        {            string user_IP = string.Empty;
            if (System.Web.HttpContext.Current.Request.ServerVariables["HTTP_VIA"] != null)
            {
                if (System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"] != null)
                {
                    user_IP = System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"].ToString();
                }
                else
                {
                    user_IP = System.Web.HttpContext.Current.Request.UserHostAddress;
                }
            }
            else
            {
                user_IP = System.Web.HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"].ToString();
            }
            return user_IP;
        }

Answer 4

IPHostEntry oIPHost = Dns.GetHostEntry(Environment.MachineName);
            if (oIPHost.AddressList.Length > 0)
{
oIPHost.AddressList[]里面找非内网地址
}

Answer 5

HttpContext.Current.Request.UserHostAddress

Answer 6

你弄一个 web服务器
用ip访问 会先经过路由再转发回来 就可以知道路由的ip