WPF: TreeView example (Part 3)

Continuing from the last post, let us add another level to our tree. For this we have to:

1> Change the DataTemplate to HierarchicalDataTemplate for the second level
2> Add a new DataTemplate to show the third level

The classes used in the sample:

    public class Category
    {
        public string Name
        { get; set; }
        public List<Company> ItemList
        { get; set; }
    }
    public class Company
    {
        public string Name
        { get; set; }
        public List<Product> Products
        { get; set; }
    }
    public class Product
    {
        public string Name
        { get; set; }
    }

Loading data in Window class:

  private void Load()
        {
            Company cMS = new Company { Name = "Microsoft", Products = new List<Product>() { new Product { Name = "Windows" }, new Product { Name = "MS Office" } } };
            Company cApple = new Company { Name = "Apple", Products = new List<Product>() { new Product { Name = "iPhone" }, new Product { Name = "iPad" }, new Product { Name = "Mac" } } };
            Company cIntel = new Company { Name = "Intel", Products = new List<Product>() { new Product { Name = "i5 Processor" }, new Product { Name = "i3 Processor" } } };
            Company cAMD = new Company { Name = "AMD", Products = new List<Product>() { new Product { Name = "Processor" } } };
            Category cSoftware = new Category { Name = "Software Companies", ItemList = new List<Company>() { cMS, cApple } };
            Category cHardware = new Category { Name = "Hardware Companies", ItemList = new List<Company>() { cIntel, cAMD } };
            List<Category> categories = new List<Category>();
            categories.Add(cSoftware);
            categories.Add(cHardware);
            tv.DataContext = categories;
        }

Modifying the XAML:

  <TreeView Name="tv" ItemsSource="{Binding}">
            <TreeView.Resources>
                <DataTemplate x:Key="productsTemplate">
                    <TextBlock Text="{Binding Path=Name}" />
                </DataTemplate>
                <HierarchicalDataTemplate x:Key="companyTemplate" ItemsSource="{Binding Path=Products}" ItemTemplate="{StaticResource ResourceKey=productsTemplate}">
                    <TextBlock Text="{Binding Path=Name}" />
                </HierarchicalDataTemplate>
            </TreeView.Resources>
            <TreeView.ItemTemplate>
                <HierarchicalDataTemplate ItemsSource="{Binding Path=ItemList}" ItemTemplate="{StaticResource ResourceKey=companyTemplate}">
                    <Border BorderBrush="BurlyWood" BorderThickness="2">
                        <TextBlock Text="{Binding Path=Name}" />
                    </Border>
                </HierarchicalDataTemplate>
            </TreeView.ItemTemplate>
        </TreeView>

Result: