C# Web 获取客户端IP

#region 获取web客户端ip

/// <summary>
/// 获取web客户端ip
/// </summary>
/// <returns></returns>
public static string GetWebClientIp()
{

string userIP = "未获取用户IP";

try
{
if (System.Web.HttpContext.Current == null
|| System.Web.HttpContext.Current.Request == null
|| System.Web.HttpContext.Current.Request.ServerVariables == null)
return "";

string CustomerIP = "";

//CDN加速后取到的IP simone 090805
CustomerIP = System.Web.HttpContext.Current.Request.Headers["Cdn-Src-Ip"];
if (!string.IsNullOrEmpty(CustomerIP))
{
return CustomerIP;
}

CustomerIP = System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];

if (!String.IsNullOrEmpty(CustomerIP))
return CustomerIP;

if (System.Web.HttpContext.Current.Request.ServerVariables["HTTP_VIA"] != null)
{
CustomerIP = System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
if (CustomerIP == null)
CustomerIP = System.Web.HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
}
else
{
CustomerIP = System.Web.HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];

}

if (string.Compare(CustomerIP, "unknown", true) == 0)
return System.Web.HttpContext.Current.Request.UserHostAddress;
return CustomerIP;
}
catch { }

return userIP;

}
#endregion