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Version: 0.10.x

TreeView

The TreeView is a control that presents hierarchical tree data and allows selection of it.

One example for populating a TreeView can be from a directory on the computer. You can create a TreeView in the MainWindow.axaml file in an Avalonia MVVM project.

<TreeView Items="{Binding Items}" 
Width="400" Height="480"
HorizontalAlignment="Left">
<TreeView.ItemTemplate>
<TreeDataTemplate ItemsSource="{Binding Subfolders}">
<TextBlock Text="{Binding strNodeText}"/>
</TreeDataTemplate>
</TreeView.ItemTemplate>
</TreeView>

In the MainWindowViewModel.cs you can add this code which will recursively look up all the subfolders and populate the TreeView from Items and Subfolders

public ObservableCollection<Node> Items { get; }
public ObservableCollection<Node> SelectedItems { get; }
public string strFolder { get; set; }

public MainWindowViewModel()
{
strFolder = @"C:\Users\hooty\Desktop"; // EDIT THIS FOR AN EXISTING FOLDER

Items = new ObservableCollection<Node>();

Node rootNode = new Node(strFolder);
rootNode.Subfolders = GetSubfolders(strFolder);

Items.Add(rootNode);
}

public ObservableCollection<Node> GetSubfolders(string strPath)
{
ObservableCollection<Node> subfolders = new ObservableCollection<Node>();
string[] subdirs = Directory.GetDirectories(strPath, "*", SearchOption.TopDirectoryOnly);

foreach (string dir in subdirs)
{
Node thisnode = new Node(dir);

if (Directory.GetDirectories(dir, "*", SearchOption.TopDirectoryOnly).Length > 0)
{
thisnode.Subfolders = new ObservableCollection<Node>();

thisnode.Subfolders = GetSubfolders(dir);
}

subfolders.Add(thisnode);
}

return subfolders;
}

public class Node
{
public ObservableCollection<Node> Subfolders { get; set; }

public string strNodeText { get; }
public string strFullPath { get; }

public Node(string _strFullPath)
{
strFullPath = _strFullPath;
strNodeText = Path.GetFileName(_strFullPath);
}
}

The example project source can be found at avalonia-treeview-test

Reference

TreeView

Source code

TreeView.cs