获取客户端IP地址

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();
}
if (user_IP.Contains(','))
{
user_IP = user_IP.Split(',')[0];
}
return user_IP;
}