LINQ TO XML

XElement config = XElement.Parse (
@"<configuration>
    <client name='setting1' enabled='true'>
        <timeout>30</timeout>
    </client>
    <client name='setting2' enabled='false'>
        <timeout>90</timeout>
    </client>
</configuration>");

foreach (XElement child in config.Elements())
    child.Name.Dump ("Child element name");
XElement client = config.Element ("client");
bool enabled = (bool) client.Attribute ("enabled");   // Read attribute --client
enabled.Dump ("enabled attribute");
client.Attribute ("enabled").SetValue (!enabled);     // Update attribute --True
int timeout = (int) client.Element ("timeout");       // Read element--30
timeout.Dump ("timeout element");
client.Element ("timeout").SetValue (timeout * 2);    // Update element
client.Add (new XElement ("retries", 3));             // Add new elememt
config.Dump ("Updated DOM");
config.Descendants ("client").Count().Dump ("Count of all clients");//2
config.Elements ("client").Count().Dump("Count of Elements");//2
config.FirstNode.Dump ("FirstNode");
config.FirstNode.AddAnnotation ("Hello FirstNode");//增加注释
config.FirstNode.Annotation<string>().Dump ("String annotations");
config.FirstNode.RemoveAnnotations<string>();//移除注释
config.FirstNode.Annotation<string>().Dump ("String annotations");
config.FirstNode.Dump ("Hello FirstNode");
config.LastNode.Dump ("LastNode");
config.FirstNode.AddAfterSelf(new XElement ("client",new XElement ("timeout",120),new XElement ("retries",30)));
config.Dump("After calling items.FirstNode.AddAfterSelf");
config.FirstNode.ReplaceWith (new XComment ("client was here"));
config.Dump("Notice to change of FirstNode ");
config.FirstNode.Remove();
config.Dump("After");
//config.Add(new XElement ("client",new XElement ("timeout", new XText ("12"),new XText ("0"))));
config.Add(new XElement ("client",new XAttribute ("id", "IDProperty"),new XElement ("timeout", "12","0")));
config.Dump("After of Add");

StreamingElement

new XStreamingElement ("customers",
    from c in Customers
        where c.ID==4
        select 
            new XStreamingElement ("customer", new XAttribute ("id", c.ID),
                new XElement ("name", c.Name),
                new XElement ("buys", c.Purchases.Count)
            )
        )

        Result:    

 <customers> <customer id="4"> <name>Mary</name> <buys>3</buys> </customer> </customers>

Transforming an X-DOM

 

void Main()
{
    XElement project = XElement.Parse (@"
    <Project DefaultTargets=""Build"" xmlns=""http://schemas.microsoft.com/developer/msbuild/2003"">
        <PropertyGroup>
            <Platform Condition="" '$(Platform)' == '' "">AnyCPU</Platform>
            <ProductVersion>9.0.11209</ProductVersion>
        </PropertyGroup>
        <ItemGroup>
            <Compile Include=""ObjectGraph.cs"" />
            <Compile Include=""Program.cs"" />
            <Compile Include=""Properties\AssemblyInfo.cs"" />
            <Compile Include=""Tests\Aggregation.cs"" />
            <Compile Include=""Tests\Advanced\RecursiveXml.cs"" />
        </ItemGroup>
    </Project>");
    
    XNamespace ns = project.Name.Namespace;
    
    IEnumerable<string> paths =
        from compileItem in project.Elements (ns + "ItemGroup").Elements (ns + "Compile")
        let include = compileItem.Attribute ("Include")
        where include != null
        select include.Value;
        
    var query = new XElement ("Project", ExpandPaths (paths));
        
    query.Dump();
}

static IEnumerable<XElement> ExpandPaths (IEnumerable<string> paths)
{
    var brokenUp =
        from path in paths
        let split = path.Split (new char[] { '\\' }, 2)
        orderby split[0]
        select new
        {
            name = split[0],
            remainder = split.ElementAtOrDefault (1)
        };

    IEnumerable<XElement> files =
        from b in brokenUp
        where b.remainder == null
        select new XElement ("file", b.name);

    IEnumerable<XElement> folders =
        from b in brokenUp
        where b.remainder != null
        group b.remainder by b.name into grp
        select new XElement ("folder",
            new XAttribute ("name", grp.Key),
            ExpandPaths (grp)
        );

    return files.Concat (folders);
}

 

result:

 

<Project>
  <file>ObjectGraph.cs</file>
  <file>Program.cs</file>
  <folder name="Properties">
    <file>AssemblyInfo.cs</file>
  </folder>
  <folder name="Tests">
    <file>Aggregation.cs</file>
    <folder name="Advanced">
      <file>RecursiveXml.cs</file>
    </folder>
  </folder>
</Project>