c# – 使用PreserveWhitespace LoadOptions在XDocument中添加带

<root>
    <files>
        <file>a</file>

        <file>b</file>
        <file>c</file>



        <file>d</file>
    </files>
</root>

所以我使用XDocument xDoc = XDocument.Load(path,LoadOptions.PreserveWhitespace)加载xml文档;
但是当我试图添加新元素xDoc.Root.Element(“files”)时.添加(new XElement(“test”,“test”));
xDoc.Root.Element(“files”).Add(new XElement(“test2”,“test2”));
它添加在同一行,因此输出如下：

<root>
    <files>
        <file>a</file>

        <file>b</file>
        <file>c</file>



        <file>d</file>
    <test>test</test><test2>test2</test2></files>
</root>

那么如何在新行中添加新元素以节省初始格式？我尝试使用带有Setting.Indent = true的XmlWriter来保存XDocument,但正如我所见,当我使用xDoc.Root.Element()时,元素被添加到同一行.Add()

更新：程序加载,修改和保存文档的完整部分

using System;
using System.Xml;
using System.Xml.Linq;
using System.Text;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {            
            string path = @".doc.xml";    
            XDocument xDoc = XDocument.Load(path,LoadOptions.PreserveWhitespace);

            //when i debug i see in "watch" that after these commands new elements are already added in same line
            xDoc.Descendants("files").First().Add(new XElement("test","test"));
            xDoc.Descendants("files").First().Add(new XElement("test2","test2"));

            XmlWriterSettings settings = new XmlWriterSettings();
            settings.Encoding = Encoding.UTF8;
            settings.Indent = true;
            settings.IndentChars = "t";

            using (XmlWriter writer = XmlTextWriter.Create(path,settings))
            {                
                xDoc.Save(writer);
                //Here i also tried save without writer - xDoc.Save(path)
            }
        }
    }
}