asp.net 获取客户机IP地址

/// <summary>

///get  client IP

/// </summary>

/// <returns></returns>

public static string GetIP()

{

    string clientIP = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];

    if (String.IsNullOrEmpty(clientIP))

    {

        clientIP = HttpContext.Current.Request.ServerVariables["HTTP_X_REAL_IP"];

    }

    if (string.IsNullOrEmpty(clientIP))

    {

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

    }

    return clientIP;

}