Simple Nested TreeView Xaml structure?

Question

I am trying to build a WPF TreeView with three layers. CountryReportTitle is a string property and ArticleCategoryTitlesList is a coll

Answer 1

Here's my go-to example for treeviews.

Use a HierarchicalDataTemplate for elements in the tree. Note that there are three layers, and each layer is its own type. This is for convenience, but you could define one type and use one template or any mix of types for your tree. Having different types represent different things in the tree makes using templates extremely convenient.

The data classes

public class ViewModel
{
    public ObservableCollection ItemsA { get; set; }
    public ViewModel()
    {
        ItemsA = new ObservableCollection(new[]{
            new ItemA{Name = "A one"},
            new ItemA{Name = "A Two"},
            new ItemA{Name = "A Three"},
        });
    }
}

public class ItemA
{
    public ObservableCollection ItemsB { get; set; }
    public string Name { get; set; }
    public ItemA()
    {
        ItemsB = new ObservableCollection(new[]{
            new ItemB{Name = "B one"},
            new ItemB{Name = "B Two"},
            new ItemB{Name = "B Three"},
        });
    }
}
public class ItemB
{
    public ObservableCollection ItemsC { get; set; }
    public string Name { get; set; }
    public ItemB()
    {
        ItemsC = new ObservableCollection(new[]{
            new ItemC{Name = "C one"},
            new ItemC{Name = "C Two"},
            new ItemC{Name = "C Three"},
        });
    }
}
public class ItemC
{
    public string Name { get; set; }
}

And the UI

gives you a simple treeview