LINQ to XML:如何替换XCData的内容

using System;using System.Linq;using System.Xml.Linq;namespace ConsoleApplication1{    class Program    {        static void Main(string[] args)        {            //写入CDATA元素块            var doc =                new XElement("Test",                    new XElement("User",                        new XAttribute("name", "chenxizhang"),                        new XCData("这是XCData的内容，可以包含特殊字符，例如< 或者 >")));            Console.WriteLine("写入CData元素");            Console.WriteLine(doc.ToString());            

doc.Element("User").FirstNode.ReplaceWith(new XCData("新的文本内容"));

            Console.Write(doc.Element("User").Value);        }    }}

.csharpcode, .csharpcode pre{font-size: small;color: black;font-family: consolas, "Courier New", courier, monospace;background-color: #ffffff;/*white-space: pre;*/}.csharpcode pre { margin: 0em; }.csharpcode .rem { color: #008000; }.csharpcode .kwrd { color: #0000ff; }.csharpcode .str { color: #006080; }.csharpcode .op { color: #0000c0; }.csharpcode .preproc { color: #cc6633; }.csharpcode .asp { background-color: #ffff00; }.csharpcode .html { color: #800000; }.csharpcode .attr { color: #ff0000; }.csharpcode .alt {background-color: #f4f4f4;width: 100%;margin: 0em;}.csharpcode .lnum { color: #606060; }