Silverlight Treeview inline HierarchicalDataTemplate binding issue - silverlight

Question

I have MyCollection of MyPOCO object (that has two string properties).
When I try to implement a HierarchicalDataTemplate into a treeview the binding is not working, I get the class name.
I know that if i take out the datatemplate from the control everything works fine but i am interested to see why this example is not working.
<Grid x:Name="LayoutRoot" Background="White" DataContext="{Binding Source={StaticResource testVM}}">
<sdk:TreeView Margin="8,8,8,111" ItemsSource="{Binding MyCollection}">
<sdk:HierarchicalDataTemplate ItemsSource="{Binding MyPOCO}">
<sdk:HierarchicalDataTemplate.ItemTemplate>
<DataTemplate>
<StackPanel>
<TextBlock Text="{Binding Property1}"/>
<TextBlock Text="{Binding Property2}"/>
</StackPanel>
</DataTemplate>
</sdk:HierarchicalDataTemplate.ItemTemplate>
</sdk:HierarchicalDataTemplate>
</sdk:TreeView>
</Grid>
Here is the ViewModel also.
namespace MyPOCProject
{
public class MyPOCO
{
private string property1;
public string Property1
{
get { return property1; }
set { property1 = value; }
}
private string property2;
public string Property2
{
get { return property2; }
set { property2 = value; }
}
public MyPOCO(string p1, string p2)
{
property1 = p1;
property2 = p2;
}
}
public class MyViewModel : INotifyPropertyChanged
{
private ObservableCollection<MyPOCO> myCollection;
public ObservableCollection<MyPOCO> MyCollection
{
get { return myCollection; }
set { myCollection = value; RaisePropertyChanged("MyCollection"); }
}
public MyViewModel()
{
MyPOCO _poco1 = new MyPOCO("aaa1", "bbb1");
MyPOCO _poco2 = new MyPOCO("aaa2", "bbb2");
MyPOCO _poco3 = new MyPOCO("aaa3", "bbb3");
MyCollection = new ObservableCollection<MyPOCO>() { _poco1, _poco2, _poco3 };
}
public event PropertyChangedEventHandler PropertyChanged;
private void RaisePropertyChanged(string propertyName)
{
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
}
So what am I doing wrong?
AGAIN ... I am interested in this particular example. I want to know what's wrong with this example and why.
Thanks.

Answer 1

The code you posted is not hierarchical, In other words: The MyPOCO Class is not containing a property MyCollection<MYPOCO> Children.
Here is an example for the HierarchicalDataTemplate
Xaml:
<sdk:TreeView x:Name="MyTreeView"
HorizontalAlignment="Left"
ItemsSource="{Binding MyCollection}"
Width="200" Height="280">
<sdk:TreeView.ItemTemplate>
<sdk:HierarchicalDataTemplate ItemsSource="{Binding Path=Children}">
<TextBlock Text="{Binding Path=Header}"/>
<sdk:HierarchicalDataTemplate.ItemTemplate>
<sdk:HierarchicalDataTemplate ItemsSource="{Binding Path=Children}">
<TextBlock Text="{Binding Path=Header}"/>
</sdk:HierarchicalDataTemplate>
</sdk:HierarchicalDataTemplate.ItemTemplate>
</sdk:HierarchicalDataTemplate>
</sdk:TreeView.ItemTemplate>
</sdk:TreeView>
Codebehind classes:
public class MyPoco
{
public MyPoco(string header, int sampleChildrenCount)
{
this.Header = header;
this.Children = new ObservableCollection<MyPoco>();
if (sampleChildrenCount > 0)
{
for (int i = 0; i < sampleChildrenCount; i++)
{
string newHeader = String.Format("Test {0}", sampleChildrenCount * i);
var myPoco = new MyPoco(newHeader, sampleChildrenCount - 1)
this.Children.Add(myPoco);
}
}
}
public string Header { get; set; }
public ObservableCollection<MyPoco> Children { get; set; }
}
public class MyViewModel
{
public MyViewModel()
{
MyCollection = new ObservableCollection<MyPoco>();
for (int i = 0; i < 6; i++)
{
this.MyCollection.Add(new MyPoco(String.Format("Test {0}", i), 5));
}
}
public ObservableCollection<MyPoco> MyCollection { get; set; }
}
Codebehind startup:
public MainPage()
{
public MainPage()
{
InitializeComponent();
MyTreeView.DataContext = new MyViewModel();
}
}