Binding Hierarchical object data to ListBox - wpf

Question

I'm trying to populate a ListBox with data from an object source using data binding in WPF.
The source is an ObjectDataProvider whose data is loaded in from an xml file. I read in the XML file, filling in the appropriate data structure, then set the ObjectInstance for the ObjectDataProvider to the data structure.
Here is the data structure:
public class Element
{
public decimal myValue;
public decimal df_myValue { get { return myValue; } set { this.myValue = value; } }
}
public class BasicSet
{
public Element[] elementSet;
public Element[] df_elementSet { get { return elementSet; } set { this.elementSet = value; } }
}
public class DataSet
{
public BasicSet[] basicSet;
public BasicSet[] df_basicSet { get { return basicSet; } set { this.basicSet = value; } }
}
Here is the XAML:
<UserControl.Resources>
<ResourceDictionary>
<ObjectDataProvider x:Key="TheData" />
<DataTemplate x:Key="ElementTemplate">
<StackPanel>
<TextBox Text="{Binding, Path=df_myValue}" />
</StackPanel>
</DataTemplate>
<HierarchicalDataTemplate x:Key="ElementSetTemplate" ItemsSource="{Binding Path=df_elementSet}" ItemTemplate="{StaticResource ElementTemplate}">
</HierarchicalDataTemplate>
</ResourceDictionary>
</UserControl.Resources>
<Grid>
<ListBox ItemsSource="{StaticResource TheData}" ItemTemplate="{StaticResource ElementSetTemplate}">
</ListBox>
</Grid>
Here is the code-behind where the xml data is being loaded:
private DataSet m_dataSet;
private ObjectDataProvider mODP;
public void LoadXml(EditorContext context, XmlValidator.Context validator, XmlDocument doc)
{
mODP = FindResource("TheData") as ObjectDataProvider;
XmlSerializer xs = new XmlSerializer(typeof(DataSet));
XmlReader r = new XmlNodeReader(doc.DocumentElement);
m_dataSet = (DataSet)xs.Deserialize(r);
mODP.ObjectInstance = m_dataSet;
}
The desired result is that the ListBox would have a TextBox for each element in the data structure. Note that the data structure is hierarchical for a reason. I cannot flatten the data structure to simplify the problem.
I am certain that the xml data is being loaded correctly into the data structure, because I can place a breakpoint and check it and all the data looks fine. But when I run the program, nothing shows up in the ListBox.
Any help is appreciated.

Answer 1

I figured out the things I was doing wrong. There were several things wrong. Here are the main points:
1) I should have been using an itemsControl
2) I didn't need to use HierarchicalDataTemplate
3) I needed three levels of controls: a TextBox inside an itemsControl inside an itemsControl... and this can be accomplished using two DataTemplates. The top-level itemsControl refers to a DataTemplate that holds an inner itemsControl. That itemsControl then refers to a DataTemplate that holds an inner TextBox.
And here is the correct xaml:
<UserControl.Resources>
<ResourceDictionary>
<ObjectDataProvider x:Key="TheData" />
<DataTemplate x:Key="ElementTemplate">
<TextBox Text="{Binding Path=df_myValue}"/>
</DataTemplate>
<DataTemplate x:Key="ElementSetTemplate">
<GroupBox Header="I am a GroupBox">
<ItemsControl ItemsSource="{Binding Path=df_elementSet}" ItemTemplate="{StaticResource ElementTemplate}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
</GroupBox>
</DataTemplate>
</ResourceDictionary>
</UserControl.Resources>
<Grid>
<ItemsControl ItemsSource="{Binding Source={StaticResource TheData}, Path=df_basicSet}" ItemTemplate="{StaticResource ElementSetTemplate}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<StackPanel />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
</ItemsControl>
</Grid>
Hope this helps someone else...