using DevExpress.XtraTreeList;
using DevExpress.XtraTreeList.Columns;

// Represents a sample Business Object
public class MyData : TreeList.IVirtualTreeListData {
    protected MyData parentCore;
    protected ArrayList childrenCore = new ArrayList();
    protected object[] cellsCore;

    public MyData(MyData parent, object[] cells) {
        // Specifies the parent node for the new node.
        this.parentCore = parent;
        // Provides data for the node's cell.
        this.cellsCore = cells;
        if (this.parentCore != null) {
            this.parentCore.childrenCore.Add(this);
        }
    }
    void TreeList.IVirtualTreeListData.VirtualTreeGetChildNodes(
    VirtualTreeGetChildNodesInfo info) {
        info.Children = childrenCore;
    }
    void TreeList.IVirtualTreeListData.VirtualTreeGetCellValue(
    VirtualTreeGetCellValueInfo info) {
        info.CellData = cellsCore[info.Column.AbsoluteIndex];
    }

    void TreeList.IVirtualTreeListData.VirtualTreeSetCellValue(VirtualTreeSetCellValueInfo info) {
        cellsCore[info.Column.AbsoluteIndex] = info.NewCellData;
    }
}

Imports DevExpress.XtraTreeList
Imports DevExpress.XtraTreeList.Columns

' Represents a sample Business Object.
Public Class MyData
    Implements TreeList.IVirtualTreeListData
    Protected parentCore As MyData
    Protected childrenCore As New ArrayList()
    Protected cellsCore() As Object


    Public Sub New(ByVal parent As MyData, ByVal cells() As Object)
        ' Specifies the parent node for the new node.
        Me.parentCore = parent
        ' Provides data for the node's cell.
        Me.cellsCore = cells
        If Not (Me.parentCore Is Nothing) Then
            Me.parentCore.childrenCore.Add(Me)
        End If
    End Sub

    Sub VirtualTreeGetChildNodes(ByVal info As VirtualTreeGetChildNodesInfo) _
    Implements TreeList.IVirtualTreeListData.VirtualTreeGetChildNodes
        info.Children = childrenCore
    End Sub

    Sub VirtualTreeGetCellValue(ByVal info As VirtualTreeGetCellValueInfo) _
    Implements TreeList.IVirtualTreeListData.VirtualTreeGetCellValue
        info.CellData = cellsCore(info.Column.AbsoluteIndex)
    End Sub

    Sub VirtualTreeSetCellValue(ByVal info As VirtualTreeSetCellValueInfo) _
    Implements TreeList.IVirtualTreeListData.VirtualTreeSetCellValue
        cellsCore(info.Column.AbsoluteIndex) = info.NewCellData
    End Sub

End Class

public partial class Form1 : Form {
    public Form1() {
        InitializeComponent();
        InitData();
    }
    void InitData() {
        // Represents the root of the tree.
        MyData tlDataSource = new MyData(null, null);
        // Represents the first root node.
        MyData rootNode1 = new MyData(tlDataSource, new string[] { "Project A", "High" });
        MyData node1 = new MyData(rootNode1, new string[] { "Deliverable 1", "Normal" });
        MyData node2 = new MyData(node1, new string[] { "This task is mine A", "High" });
        MyData node3 = new MyData(node1, new string[] { "This task isn't mine A", "Low" });
        // Represents the second root node.
        MyData rootNode2 = new MyData(tlDataSource, new string[] { "Project B", "Normal" });
        // Represents the child node of the second root node.
        MyData node5 = new MyData(rootNode2, new string[] { "This task is mine B", "High" });
        treeList1.DataSource = tlDataSource;
        TreeListColumn col1 = new TreeListColumn();
        col1.Caption = "Name";
        col1.VisibleIndex = 0;
        TreeListColumn col2 = new TreeListColumn();
        col2.Caption = "Priority";
        col2.VisibleIndex = 1;
        treeList1.Columns.AddRange(new TreeListColumn[] {col1, col2});            
    }
}

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        InitData()
    End Sub

    Sub InitData()
        ' Represents the root of the tree.
        Dim tlDataSource = New MyData(Nothing, Nothing)
        ' Represents the first root node.
        Dim rootNode1 = New MyData(tlDataSource, New String() {"Project A", "High"})
        Dim node1 = New MyData(rootNode1, New String() {"Deliverable 1", "Normal"})
        Dim node2 = New MyData(node1, New String() {"This task is mine A", "High"})
        Dim node3 = New MyData(node1, New String() {"This task isn't mine A", "Low"})
        ' Represents the second root node.
        Dim rootNode2 = New MyData(tlDataSource, New String() {"Project B", "Normal"})
        ' Represents the child node of the second root node.
        Dim node5 = New MyData(rootNode2, New String() {"This task is mine B", "High"})
        TreeList1.DataSource = tlDataSource
        Dim col1 As TreeListColumn = New TreeListColumn()
        col1.Caption = "Name"
        col1.VisibleIndex = 0
        Dim col2 As TreeListColumn = New TreeListColumn()
        col2.Caption = "Priority"
        col2.VisibleIndex = 1
        TreeList1.Columns.AddRange(New TreeListColumn() {col1, col2})
    End Sub
End Class