Folder Tree WPF Control: Part 2 - Selection Events

FolderTree.xaml.cs

public partial class FolderTree : UserControl
{
    private FolderTreeSelection _selection;
    public FolderTreeSelection Selection
    {
        get { return _selection; }
        set
        {
            _selection = value;
            _selection.Changed += new EventHandler(OnSelectionChanged);
        }
    }

    public event EventHandler SelectionChanged;

    public FolderTree()
    {
        InitializeComponent();

        Selection = new FolderTreeSelection();
    }

    ...

    private void OnSelectionChanged(object sender, EventArgs args)
    {
        if (SelectionChanged != null)
        {
            SelectionChanged(sender, args);
        }
    }
}

FolderTreeSelection.cs

public class FolderTreeSelection : ViewModelBase
{
    ...
    public event EventHandler Changed;
    ...
    private void OnChanged()
    {
        if (Changed != null)
        {
            Changed(this, new EventArgs());
        }
    }
}

MainWindow-cleaner.xaml

<Window x:Class="Demo.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:ftc="clr-namespace:GeekJ.FolderTreeControl;assembly=GeekJ.FolderTreeControl"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <ftc:FolderTree SelectionChanged="FolderTreeSelection_Changed" />
    </Grid>
</Window>

MainWindow.xaml

<Window x:Class="Demo.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:ftc="clr-namespace:GeekJ.FolderTreeControl;assembly=GeekJ.FolderTreeControl"
        xmlns:ftcModel="clr-namespace:GeekJ.FolderTreeControl.Model;assembly=GeekJ.FolderTreeControl"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <ftc:FolderTree>
            <ftc:FolderTree.Selection>
                <ftcModel:FolderTreeSelection Changed="FolderTreeSelection_Changed" />
            </ftc:FolderTree.Selection>
        </ftc:FolderTree>
    </Grid>
</Window>