c#，如何读取XML内部元素

我有一个xml文件，其中列出了我需要读取以生成string[]的一堆文件。我可以识别xml文件中的每个ProjectGroup:

XmlNodeList projectsGroup = doc.SelectNodes("//ProjectGroups/ProjectGroup");
if (projectsGroup != null)
{
    foreach (XmlNode projectNode in projectsGroup)
    {
         //Need to read inside the ProjectGroup, how?
    }
}

使用这段代码，我可以创建每个ProjectGroup的列表。我如何在每个项目中读取文件列表?下面是我正在使用的xml文件:

<ProjectGroups>
    <ProjectGroup Name = "InvGroup">
    <Out>
      <Project Name="Inv.Commands" In="false" LC="false">
        <File>Inv.Commands.dll</File>
        <File>Inv.Commands.pdb</File>
        <File>Inv.Commands.xml</File>
      </Project>
      <Project Name="Inv.Common" In="false" LC="false">
        <File>Inv.Common.dll</File>
        <File>Inv.Common.pdb</File>
        <File>Inv.Common.xml</File>
      </Project>
     </Out>
    </ProjectGroup>
    <ProjectGroup Name = "RATGroup">
    <Out>
      <Project Name="DB_RAT" In="false" LC="false" IF="" />
      <Project Name="AnalyzeData" In="false" LC="true" IF="">
        <File>AnalyzeData.dll</File>
        <File>AnalyzeData.pdb</File>
        <File>AnalyzeData.xml</File>
      </Project>
      <Project Name="Commands.GetCh" In="false" LC="true" IF="">
        <File>Commands.GetCh.dll</File>
        <File>Commands.GetCh.pdb</File>
        <File>Commands.GetCh.xml</File>
      </Project>
    </Out>
    </ProjectGroup>
</ProjectGroups>

    foreach (XmlNode projectNode in projectsGroup)
    {
         //Need to read inside the ProjectGroup, how?
         XmlNodeList files = projectNode.SelectNodes("//File");
         foreach(XmlNode fileNode in files) 
         {
            // do whatever you need to do to the "file" node here....
         }
    }

   XmlDocument doc = new XmlDocument();
   doc.Load(xmlfilepath);
   XmlNodeList nodes = doc["ProjectGroups"]["ProjectGroup"]["Out"]["Project"].ChildNodes;
   foreach(XmlNode node in nodes ) {
     //do something
   }