WPF, XAML: TreeView HierarchicalDataTemplate databinding to unknown XML/DataSource

Problem description

• I wish to bind my TreeView to a datasource.
• The TreeView should build its child nodes dynamically (unknows childs in datasource).
• Each node should display its data or (if no data) its element name.

Solution
You need to use and understand these parts:

1. HierarchicalDataTemplate
1. HierarchicalDataTemplate.Triggers
2. Binding XPath

Usage Example
Just copy paste and start playing / reading each part's help.

XAML

Code Snippet

1. <Window x:Class="TreeViewDataBinding.Window1"
2.     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
3.     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
4.     Title="Window1" Height="300" Width="300">
5.     <Window.Resources>
6.         <HierarchicalDataTemplate x:Key="NodeTemplate" >
7.  
8.             <TextBlock x:Name="tbName" Text="?" />
9.  
10.             <HierarchicalDataTemplate.ItemsSource>
11.                 <Binding XPath="child::node()" />
12.             </HierarchicalDataTemplate.ItemsSource>
13.  
14.             <HierarchicalDataTemplate.Triggers>
15.                 <DataTrigger Binding="{Binding Path=NodeType}" Value="Text">
16.                     <Setter TargetName="tbName" Property="Text" Value="{Binding Path=Value}"/>
17.                 </DataTrigger>
18.                 <DataTrigger Binding="{Binding Path=NodeType}" Value="Element">
19.                     <Setter TargetName="tbName" Property="Text" Value="{Binding Path=Name}"/>
20.                 </DataTrigger>
21.             </HierarchicalDataTemplate.Triggers>
22.         </HierarchicalDataTemplate>
23.  
24.         <XmlDataProvider x:Key="xmlDataProvider"/>
25.     </Window.Resources>
26.     
27.     <StackPanel>
28.         <Button Click="Button_Click">Reload</Button>
29.         
30.         <TreeView
31.             ItemsSource="{Binding Source={StaticResource xmlDataProvider}, XPath=*}"
32.             ItemTemplate="{StaticResource NodeTemplate}" />
33.     </StackPanel>
34. </Window>

Code behind

Code Snippet

1. using System.Windows;
2. using System.Windows.Data;
3. using System;
4.  
5. namespace TreeViewDataBinding
6. {
7.     public partial class Window1 : Window
8.     {
9.         public Window1()
10.         {
11.             InitializeComponent();
12.         }
13.  
14.         private void Button_Click(object sender, RoutedEventArgs e)
15.         {
16.             var provider = (XmlDataProvider)this.Resources["xmlDataProvider"];
17.             provider.Source = new Uri(@"Data\standard.xml", UriKind.Relative);
18.         }
19.     }
20. }

Additional files

• standard.xml testbenach XML file (100MB !!).
• http://www.xml-benchmark.org/downloads.html
• " For your convenience, we provide a ready-made document for a 100 MB experiment."

Performance
I was able to load 100MB of xml data in around ~6 seconds first time, ~4 seconds from the second time.

Testbench station

• i7 (8 cores) @ 2.80GHz
• 4.00GB RAM
• 64-Bit OS, Win7 Pro.

CPU & memory usage

The CPU was at idle when i started, the RAM was at the base line.

Results

Resources

• http://www.w3schools.com/xpath/xpath_syntax.asp
• http://www.w3schools.com/xpath/xpath_axes.asp
• http://stackoverflow.com/questions/1605062/treeview-bound-to-xmldataprovider-shows-data-in-editor-but-empty-when-run

Hope it helps.

About WPF

Here is my experiance with learning and programming WPF in the last year:

First let me tell you that - WPF IS GREAT!
Simple put - WPF let you do layers of controls and decorators.
This means you can composite anything in easy.
The things I did with WPF were not easy at all in Win32-API and not even in .Net using GDI+.

Let's start with a complext WPF sample I've found:

http://10rem.net/blog/2010/10/28/the-present-and-future-of-wpf

Usage example

I wish to have a character drawn, later on I wish to add that character a life status, later on - an icon on the top-right to reperesent which guild is he in... and more...

Of course It's solvable using the Decorator-Pattern using the draw to add more pictures, but - you need to BitBlt ... and more complex stuff.

With WPF, however, you layer it all with opacity, or transparency, which is the same solution as before with one exception - you write it declarativly and in 10 min :-).

The learning curve

I already had a very rich epreriance with WinForms/MFC/Win32 GUI + I know Design-Patterns pretty good, so I had a good head-start ==> It was easier to learn, the elements were already in my mind.

First I started with tutorials to feel WPF, and books.
The most used were (recomendation ordered):

1. Tutorials:
1. WPF Tutorial
2. 'Hello WPF' ... http://www.wpftutorial.net/HelloWPF.html
2. Books:
1. http://www.amazon.com/Sams-Teach-Yourself-WPF-Hours/dp/0672329859
2. http://www.amazon.com/2010-NET-Platform-Andrew-Troelsen/dp/1430225491
1. The chapters about WPF (Chapter 27).

In between, I started using it in my solutions, strted with simple solutions (traditional GUI programming), used the known and common parts (buttons, labels, textboxes...), practiced and learned the basics.

Bottom line 
After touching WPF there is no going back, I'll always prefer WPF over other solutions, unless I have no choice, like - "the OS doesn't support DirectX 9" :-(.

Have a good and productive learning - WPF worth it!

Resources

• http://www.wpftutorial.net/Home.html
• Amazon
• http://msdn.microsoft.com/en-us/library/ms754130.aspx
• http://windowsclient.net/