Nested TreeView Heirarchy Generation

Question

If the following code produces this tree:

The Flanders

    Ned

    Maude

    Todd

    Rod

what code would produce this tree?

The Flanders

    Ned

         Maude

                Todd

                 Rod

    Frank

The Simpsons

    Homer   

??

    public class FlandersViewModel
    {
        public FlandersViewModel()
        {

            Name = "The Flanders";

            Children = new ObservableCollection<Person>();

            Children.Add(new Person { Name = "Ned" });
            Children.Add(new Person { Name = "Maude" });
            Children.Add(new Person { Name = "Todd" });
            Children.Add(new Person { Name = "Rod" });
        }

        public string Name { get; set; }

        public ObservableCollection<Person> Children { get; set; }

    }

    public class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }

    }
}

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REvans

Answer 1

Hi

You need to add the "Children" collection property also to the "Person" class
to enable a family tree with more than one level of (grand)children.

The tree is built up by adding persons to other persons Children
collectiion recursively.

Chris

For example:

using System.Collections.ObjectModel;
using System.Windows;

namespace WpfApplication1
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeData();
            InitializeComponent();
        }
        private void InitializeData()
        {
            //Build Family trees
            var flanders = new Family { Name = "The Flanders" };
            var ned = new Person { Name = "Ned" };
            var maude = new Person { Name = "Maude" };
            var todd = new Person { Name = "Todd" };
            var rod = new Person { Name = "Rod" };

            maude.Children.Add(todd);
            maude.Children.Add(rod);
            ned.Children.Add(maude);
            flanders.Children.Add(ned);

            var simpsons = new Family { Name = "The Simpsons" };
            var homer = new Person { Name = "Homer" };
            simpsons.Children.Add(homer);
            
            var viewModel = new MainViewModel();
            viewModel.Families.Add(flanders);
            viewModel.Families.Add(simpsons);
     
            DataContext = viewModel;
        }
    }
    public class MainViewModel //TODO impl. INotifyPropertyChanged
    {
        public MainViewModel()
        {
            Families = new ObservableCollection<Family>();
        }
        public ObservableCollection<Family> Families { get; private set; }
    }
    public class Family : NodeBase
    {
    }
    public class Person : NodeBase
    {
        public int Age { get; set; }
    }
    public abstract class NodeBase
    {
        protected NodeBase()
        {
            Children = new ObservableCollection<Person>();
        }
        public string Name { get; set; }
        public ObservableCollection<Person> Children { get; private set; }
    }
}

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <TreeView ItemsSource="{Binding Path=Families}">
        <TreeView.ItemTemplate>
            <HierarchicalDataTemplate  ItemsSource="{Binding Path=Children}">
                <TextBlock Text="{Binding Path=Name}" />
            </HierarchicalDataTemplate>
        </TreeView.ItemTemplate>
        <TreeView.ItemContainerStyle>
            <Style>
                <Setter Property="TreeViewItem.IsExpanded" Value="True" />
            </Style>
        </TreeView.ItemContainerStyle>
    </TreeView>
</Window>

Answer 2

Thank you, very much Christian Developer.  That was exactly what I was looking for.

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REvans