string withoutCdata ="<?xml version=\"1.0\" encoding=\"UTF-8\"?>" +
            "<result><data><script>alert(\"\");</script></data></result>";

        XmlDocument doc = new XmlDocument();
        doc.LoadXml(withoutCdata);

        string value = doc.SelectSingleNode("result/data").InnerText;
        //value = alert(\"\");,其中“<script></script>“会被处理掉，得不到全部的节点内容

        string withCdata = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" +
            "<result><data><![CDATA[<script>alert(\"\");</script>]]></data></result>";
        doc.LoadXml(withCdata);

        string oriValue = doc.SelectSingleNode("result/data").InnerText;
            //oriVale = <script>alert(\"\");</script>，这样就取到全部的节点内容了