1:
2:
3:
4:
5:
6:
7:

  <TreeView ItemsSource="{Binding}">
        <TreeView.ItemTemplate>
            <HierarchicalDataTemplate ItemsSource="{Binding Children}">
                <TextBlock Text="{Binding Title}" />
            </HierarchicalDataTemplate>
        </TreeView.ItemTemplate>
    </TreeView>					

1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:
32:
33:
34:
35:
36:
37:
38:
39:
40:
41:
42:
43:
44:
45:
46:
47:
48:
49:
50:
51:
52:
53:
54:
55:
56:
57:
58:
59:
60:
61:
62:
63:
64:
65:
66:
67:

  public partial class MainWindow : Window
  {
    public MainWindow()
    {
      InitializeComponent();
      DataContext = new[] { new TocEntry("ms.help?method=page&id=-1&topicversion=100&topiclocale=EN-US&SQM=1&product=VS&productVersion=100&locale=EN-US") };
    }
  }

  class TocEntry : INotifyPropertyChanged
  {
    const string server = "http://127.0.0.1:47873/help/1-180/";
    WebClient client = new WebClient();
    Lazy<IEnumerable<TocEntry>> children;

    public TocEntry(string url)
    {
      url = url.Replace("product=&productVersion", "product=VS&productVersion");
    
      client.DownloadStringCompleted += (_, e) =>
      {
        var root = XElement.Parse(e.Result);
        var mappings = new XmlNamespaceMappingCollection {
          new XmlNamespaceMapping("x", new Uri("http://www.w3.org/1999/xhtml"))
        };

        var hrefs = (IEnumerable)root.XPathEvaluate(
          "x:body/x:div[@class='OH_outerDiv']/x:div[@id='LeftNav']/x:div[@id='toc']/x:div[@id='toc_children']/x:div[@class='OH_selfTocLinks']/x:a/@href",
          mappings);
        children = new Lazy<IEnumerable<TocEntry>>(() =>
          hrefs.Cast<XAttribute>()
          .Select(href => new TocEntry(href.Value))
          .ToArray()
        );
        RaisePropertyChanged("Children");

        Title = root.XPathSelectElement("x:head/x:title", mappings).Value;

        client.Dispose();
      };

      client.DownloadStringAsync(new Uri(server + url));
    }

    private string title = null;
    public string Title
    {
      get { return title; }
      private set
      {
        if (title != value)
        {
          title = value;
          RaisePropertyChanged("Title");
        }
      }
    }

    public IEnumerable<TocEntry> Children { get { return children != null ? children.Value : null; } }

    public event PropertyChangedEventHandler PropertyChanged;
    protected void RaisePropertyChanged(string name)
    {
      PropertyChangedEventHandler handler = PropertyChanged;
      if (handler != null) handler(this, new PropertyChangedEventArgs(name));
    }
  }					

1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:

<children id="-1" locale="de-de" product="WIN32APITUTORIALS" productversion="300">
  <topic id="WIN32API.DELPHI.BASE.INTRO">
    <title>Win32-API-Tutorials für Delphi</title> 
    <url>WIN32API.DELPHI.BASE.INTRO&topicversion=300&topiclocale=DE-DE&SQM=1</url> 
    <description /> 
  </topic>
  <topic id="FADF1F04-77DD-43FB-81F6-72E5AE0BFC3D">
    <title>Dokumentation zum Microsoft-Hilfesystem</title> 
    <url>FADF1F04-77DD-43FB-81F6-72E5AE0BFC3D&topicversion=100&topiclocale=DE-DE&SQM=1</url> 
    <description /> 
  </topic>
</children>					

1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:

client.DownloadStringCompleted += (_, e) =>
{
  var root   = XElement.Parse(e.Result);
  var topics = (IEnumerable)root.XPathEvaluate("topic/@id");
  children   = new Lazy<IEnumerable<TocEntry>>(() =>
    topics.Cast<XAttribute>()
    .Select(id => new TocEntry(id.Value))
    .ToArray()
  );
  RaisePropertyChanged("Children");

  try {
    title = root.XPathSelectElement("topic/title").Value;
  }
  catch {
    title = string.Format("{0} (Error)", topicId);
  }
  client.Dispose();
};					

1:
2:
3:
4:
5:

children   = new Lazy<IEnumerable<TocEntry>>(() =>
  root.Elements("topic")
  .Select(child => new TocEntry(child.Attribute("id").Value, child.Element("title").Value))
  .ToArray()
);					

1:

DataContext = new TocEntry(-1, "" /* oder hier irgendeinen Default-Namen wählen */).Children;					

1:
2:
3:
4:
5:
6:
7:
8:
9:

    static object[] defaultChild = new object[] { null };
    IEnumerable children;
    public IEnumerable Children
    {
      get
      {
        if (children == null && !client.IsBusy)
          client.DownloadStringAsync(new Uri(server + url));
        return children ?? defaultChild;					

1:

ms-xhelp://?method=children&id=<ID>&format=xml&product=VS&productVersion=100&locale=en-us					

1:

http://127.0.0.1:<PORT>/help/<ServerID>-<ProcessID>/ms.help?					

1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:
32:
33:
34:
35:
36:
37:
38:
39:
40:
41:
42:
43:
44:
45:
46:
47:
48:
49:
50:
51:
52:
53:
54:
55:

      DataContext = new[] { new TocEntry("-1") { Title = "Sqrt" } };
    }
  }

  class TocEntry : INotifyPropertyChanged
  {
    const string url = "http://127.0.0.1:47873/help/1-3668/ms.help?method=children&id={0}&format=xml&product=VS&productVersion=100&locale=en-us";
    string id;
    WebClient client = new WebClient();

    public TocEntry(string id)
    {
      this.id = id;

      client.DownloadStringCompleted += (_, e) =>
      {
        Debug.WriteLine(Title);
        var children = XElement.Parse(e.Result);

        Children =
            children.Elements("topic")
            .Select(link => new TocEntry(link.Attribute("id").Value) { Title = link.Element("title").Value })
            .ToArray();

        client.Dispose();
      };
    }

    public string Title { get; set; }

    static object[] defaultChild = new object[] { null };
    IEnumerable children;
    public IEnumerable Children
    {
      get
      {
        if (children == null && !client.IsBusy)
          client.DownloadStringAsync(new Uri(string.Format(url, id)));
        return children ?? defaultChild;
      }
      private set
      {
        children = value;
        RaisePropertyChanged("Children");
      }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    protected void RaisePropertyChanged(string name)
    {
      PropertyChangedEventHandler handler = PropertyChanged;
      if (handler != null) handler(this, new PropertyChangedEventArgs(name));
    }
  }
}