public class TreeListNode :
    ICloneable

Public Class TreeListNode
    Implements ICloneable

using DevExpress.XtraEditors;
using DevExpress.XtraEditors.Repository;
using DevExpress.XtraTreeList;
using DevExpress.XtraTreeList.Columns;
using DevExpress.XtraTreeList.Nodes;
using DevExpress.XtraTreeList.StyleFormatConditions;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Windows.Forms;

namespace TreeList_example {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e) {
            TreeList treeList1 = new TreeList();
            treeList1.Parent = this;
            treeList1.Dock = DockStyle.Fill; 
            //Specify the fields that arrange underlying data as a hierarchy.
            treeList1.KeyFieldName = "ID";
            treeList1.ParentFieldName = "RegionID";
            //Allow the treelist to create columns bound to the fields the KeyFieldName and ParentFieldName properties specify.
            treeList1.OptionsBehavior.PopulateServiceColumns = true;
            //Specify the data source.
            treeList1.DataSource = SalesDataGenerator.CreateData();
            //The treelist automatically creates columns for the public fields found in the data source. 
            //You do not need to call the TreeList.PopulateColumns method unless the treeList1.OptionsBehavior.AutoPopulateColumns option is disabled.

            //Change the row height.
            treeList1.RowHeight = 23;

            //Access the automatically created columns.
            TreeListColumn colRegion = treeList1.Columns["Region"];
            TreeListColumn colMarchSales = treeList1.Columns["MarchSales"];
            TreeListColumn colSeptemberSales = treeList1.Columns["SeptemberSales"];
            TreeListColumn colMarchSalesPrev = treeList1.Columns["MarchSalesPrev"];
            TreeListColumn colSeptemberSalesPrev = treeList1.Columns["SeptemberSalesPrev"];
            TreeListColumn colMarketShare = treeList1.Columns["MarketShare"];

            //Hide the key columns. An end user can access them from the Customization Form.
            treeList1.Columns[treeList1.KeyFieldName].Visible = false;
            treeList1.Columns[treeList1.ParentFieldName].Visible = false;

            //Format column headers and cell values.
            colMarchSalesPrev.Caption = "<i>Previous <b>March</b> Sales</i>";
            colSeptemberSalesPrev.Caption = "<i>Previous <b>September</b> Sales</i>";
            treeList1.OptionsView.AllowHtmlDrawHeaders = true;
            colMarchSalesPrev.AppearanceCell.Font = new System.Drawing.Font(colMarchSalesPrev.AppearanceCell.Font, System.Drawing.FontStyle.Italic);
            colSeptemberSalesPrev.AppearanceCell.Font = new System.Drawing.Font(colSeptemberSalesPrev.AppearanceCell.Font, System.Drawing.FontStyle.Italic);

            //Create two hidden unbound columns that calculate their values from expressions.
            TreeListColumn colUnboundMarchChange = treeList1.Columns.AddField("FromPrevMarchChange");
            colUnboundMarchChange.Caption = "Change from prev March";
            colUnboundMarchChange.UnboundDataType = typeof(decimal);
            colUnboundMarchChange.UnboundExpression = "[MarchSales]-[MarchSalesPrev]";
            TreeListColumn colUnboundSeptemberChange = treeList1.Columns.AddField("FromPrevSepChange");
            colUnboundSeptemberChange.Caption = "Change from prev September";
            colUnboundSeptemberChange.UnboundDataType = typeof(decimal);
            colUnboundSeptemberChange.UnboundExpression = "[SeptemberSales]-[SeptemberSalesPrev]";
            colUnboundMarchChange.OptionsColumn.ShowInCustomizationForm = false;
            colUnboundSeptemberChange.OptionsColumn.ShowInCustomizationForm = false;

            //Make the Region column read-only.
            colRegion.OptionsColumn.ReadOnly = true;

            //Sort data against the Region column.
            colRegion.SortIndex = 0;

            //Apply a filter.
            treeList1.ActiveFilterString = "[MarchSales] > 10000";

            //Calculate two total summaries against root nodes.
            colMarchSales.SummaryFooter = DevExpress.XtraTreeList.SummaryItemType.Sum;
            colMarchSales.SummaryFooterStrFormat = "Total={0:c0}";
            colMarchSales.AllNodesSummary = false;
            colSeptemberSales.SummaryFooter = DevExpress.XtraTreeList.SummaryItemType.Sum;
            colSeptemberSales.SummaryFooterStrFormat = "Total={0:c0}";
            colSeptemberSales.AllNodesSummary = false;
            treeList1.OptionsView.ShowSummaryFooter = true;

            //Use a 'SpinEdit' in-place editor for the 'sales' columns.
            RepositoryItemSpinEdit riSpinEdit = new RepositoryItemSpinEdit();
            riSpinEdit.DisplayFormat.FormatType = DevExpress.Utils.FormatType.Numeric;
            riSpinEdit.DisplayFormat.FormatString = "c0";
            treeList1.RepositoryItems.Add(riSpinEdit);
            colMarchSales.ColumnEdit = riSpinEdit;
            colMarchSalesPrev.ColumnEdit = riSpinEdit;
            colSeptemberSales.ColumnEdit = riSpinEdit;
            colSeptemberSalesPrev.ColumnEdit = riSpinEdit;

            //Apply Excel-style formatting: display predefined 'Up Arrow' and 'Down Arrow' icons based on the unbound column values.
            TreeListFormatRule rule1 = new TreeListFormatRule();
            rule1.Rule = createThreeTrianglesIconSetRule();
            rule1.Column = colUnboundMarchChange;
            rule1.ColumnApplyTo = colMarchSales;
            TreeListFormatRule rule2 = new TreeListFormatRule();
            rule2.Rule = createThreeTrianglesIconSetRule();
            rule2.Column = colUnboundSeptemberChange;
            rule2.ColumnApplyTo = colSeptemberSales;
            treeList1.FormatRules.Add(rule1);
            treeList1.FormatRules.Add(rule2);

            //Do not stretch columns to the treelist width.
            treeList1.OptionsView.AutoWidth = false;

            //Locate a node by a value it contains.
            TreeListNode node1 = treeList1.FindNodeByFieldValue("Region", "North America");
            //Focus and expand this node.
            treeList1.FocusedNode = node1;
            node1.Expanded = true;

            //Locate a node by its key field value and expand it.
            TreeListNode node2 = treeList1.FindNodeByKeyID(32);//Node 'Asia'
            node2.Expand();

            //Calculate the optimal column widths after the treelist is shown.
            this.BeginInvoke(new MethodInvoker(delegate {
                treeList1.BestFitColumns();
            }));
        }

        FormatConditionRuleIconSet createThreeTrianglesIconSetRule() {
            FormatConditionRuleIconSet ruleIconSet = new FormatConditionRuleIconSet();
            FormatConditionIconSet iconSet = ruleIconSet.IconSet = new FormatConditionIconSet();
            FormatConditionIconSetIcon icon1 = new FormatConditionIconSetIcon();
            FormatConditionIconSetIcon icon2 = new FormatConditionIconSetIcon();
            FormatConditionIconSetIcon icon3 = new FormatConditionIconSetIcon();
            //Choose predefined icons. 
            icon1.PredefinedName = "Triangles3_3.png";
            icon2.PredefinedName = "Triangles3_2.png";
            icon3.PredefinedName = "Triangles3_1.png";
            //Specify the type of threshold values. 
            iconSet.ValueType = FormatConditionValueType.Number;
            //Define ranges to which icons are applied by setting threshold values. 
            icon1.Value = Decimal.MinValue;
            icon1.ValueComparison = FormatConditionComparisonType.GreaterOrEqual;
            icon2.Value = 0;
            icon2.ValueComparison = FormatConditionComparisonType.GreaterOrEqual;
            icon3.Value = 0;
            icon3.ValueComparison = FormatConditionComparisonType.Greater;
            //Add icons to the icon set. 
            iconSet.Icons.Add(icon1);
            iconSet.Icons.Add(icon2);
            iconSet.Icons.Add(icon3);
            return ruleIconSet;
        }
    }

    public class SalesData {
        static int UniqueID = 37;
        public SalesData() {
            ID = UniqueID++;
        }
        public SalesData(int id, int regionId, string region, decimal marchSales, decimal septemberSales, decimal marchSalesPrev, decimal septermberSalesPrev, double marketShare) {
            ID = id;
            RegionID = regionId;
            Region = region;
            MarchSales = marchSales;
            SeptemberSales = septemberSales;
            MarchSalesPrev = marchSalesPrev;
            SeptemberSalesPrev = septermberSalesPrev;
            MarketShare = marketShare;
        }
        public int ID { get; set; }
        public int RegionID { get; set; }
        public string Region { get; set; }
        public decimal MarchSales { get; set; }
        public decimal SeptemberSales { get; set; }
        public decimal MarchSalesPrev { get; set; }
        public decimal SeptemberSalesPrev { get; set; }

        [DisplayFormat(DataFormatString = "p0")]
        public double MarketShare { get; set; }
    }

    public class SalesDataGenerator {
        public static List<SalesData> CreateData() {
            List<SalesData> sales = new List<SalesData>();
            sales.Add(new SalesData(0, -1, "Western Europe", 30540, 33000, 32220, 35500, .70));
            sales.Add(new SalesData(1, 0, "Austria", 22000, 28000, 26120, 28500, .92));
            sales.Add(new SalesData(2, 0, "France", 23020, 27000, 20120, 29200, .51));
            sales.Add(new SalesData(3, 0, "Germany", 30540, 33000, 32220, 35500, .93));
            sales.Add(new SalesData(4, 0, "Spain", 12900, 10300, 14300, 9900, .82));
            sales.Add(new SalesData(5, 0, "Switzerland", 9323, 10730, 7244, 9400, .14));
            sales.Add(new SalesData(6, 0, "United Kingdom", 14580, 13967, 15200, 16900, .91));

            sales.Add(new SalesData(17, -1, "Eastern Europe", 22500, 24580, 21225, 22698, .62));
            sales.Add(new SalesData(18, 17, "Belarus", 7315, 18800, 8240, 17480, .34));
            sales.Add(new SalesData(19, 17, "Bulgaria", 6300, 2821, 5200, 10880, .8));
            sales.Add(new SalesData(20, 17, "Croatia", 4200, 3890, 3880, 4430, .29));
            sales.Add(new SalesData(21, 17, "Russia", 22500, 24580, 21225, 22698, .85));

            sales.Add(new SalesData(26, -1, "North America", 31400, 32800, 30300, 31940, .84));
            sales.Add(new SalesData(27, 26, "USA", 31400, 32800, 30300, 31940, .87));
            sales.Add(new SalesData(28, 26, "Canada", 25390, 27000, 5200, 29880, .64));

            sales.Add(new SalesData(29, -1, "South America", 16380, 17590, 15400, 16680, .32));
            sales.Add(new SalesData(30, 29, "Argentina", 16380, 17590, 15400, 16680, .88));
            sales.Add(new SalesData(31, 29, "Brazil", 4560, 9480, 3900, 6100, .10));

            sales.Add(new SalesData(32, -1, "Asia", 20388, 22547, 22500, 25756, .52));
            sales.Add(new SalesData(34, 32, "India", 4642, 5320, 4200, 6470, .44));
            sales.Add(new SalesData(35, 32, "Japan", 9457, 12859, 8300, 8733, .70));
            sales.Add(new SalesData(36, 32, "China", 20388, 22547, 22500, 25756, .82));
            return sales;
        }
    }

}

Imports DevExpress.XtraEditors
Imports DevExpress.XtraEditors.Repository
Imports DevExpress.XtraTreeList
Imports DevExpress.XtraTreeList.Columns
Imports DevExpress.XtraTreeList.Nodes
Imports DevExpress.XtraTreeList.StyleFormatConditions
Imports System.ComponentModel.DataAnnotations

Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim treeList1 As TreeList = New TreeList()
        treeList1.Parent = Me
        treeList1.Dock = DockStyle.Fill
        'Specify the fields that arrange underlying data as a hierarchy.
        treeList1.KeyFieldName = "ID"
        treeList1.ParentFieldName = "RegionID"
        'Allow the treelist to create columns bound to the fields the KeyFieldName and ParentFieldName properties specify.
        treeList1.OptionsBehavior.PopulateServiceColumns = True
        'Specify the data source.
        treeList1.DataSource = SalesDataGenerator.CreateData()
        'The treelist automatically creates columns for the public fields found in the data source. 
        'You do not need to call the TreeList.PopulateColumns method unless the treeList1.OptionsBehavior.AutoPopulateColumns option is disabled.

        'Change the row height.
        treeList1.RowHeight = 23

        'Access the automatically created columns.
        Dim colRegion As TreeListColumn = treeList1.Columns("Region")
        Dim colMarchSales As TreeListColumn = treeList1.Columns("MarchSales")
        Dim colSeptemberSales As TreeListColumn = treeList1.Columns("SeptemberSales")
        Dim colMarchSalesPrev As TreeListColumn = treeList1.Columns("MarchSalesPrev")
        Dim colSeptemberSalesPrev As TreeListColumn = treeList1.Columns("SeptemberSalesPrev")
        Dim colMarketShare As TreeListColumn = treeList1.Columns("MarketShare")

        'Hide the key columns. An end user can access them from the Customization Form.
        treeList1.Columns(treeList1.KeyFieldName).Visible = False
        treeList1.Columns(treeList1.ParentFieldName).Visible = False

        'Format column headers and cell values.
        colMarchSalesPrev.Caption = "<i>Previous <b>March</b> Sales</i>"
        colSeptemberSalesPrev.Caption = "<i>Previous <b>September</b> Sales</i>"
        treeList1.OptionsView.AllowHtmlDrawHeaders = True
        colMarchSalesPrev.AppearanceCell.Font = New System.Drawing.Font(colMarchSalesPrev.AppearanceCell.Font, System.Drawing.FontStyle.Italic)
        colSeptemberSalesPrev.AppearanceCell.Font = New System.Drawing.Font(colSeptemberSalesPrev.AppearanceCell.Font, System.Drawing.FontStyle.Italic)

        'Create two hidden unbound columns that calculate their values from expressions.
        Dim colUnboundMarchChange As TreeListColumn = treeList1.Columns.AddField("FromPrevMarchChange")
        colUnboundMarchChange.Caption = "Change from prev March"
        colUnboundMarchChange.UnboundDataType = GetType(Decimal)
        colUnboundMarchChange.UnboundExpression = "[MarchSales]-[MarchSalesPrev]"
        Dim colUnboundSeptemberChange As TreeListColumn = treeList1.Columns.AddField("FromPrevSepChange")
        colUnboundSeptemberChange.Caption = "Change from prev September"
        colUnboundSeptemberChange.UnboundDataType = GetType(Decimal)
        colUnboundSeptemberChange.UnboundExpression = "[SeptemberSales]-[SeptemberSalesPrev]"
        colUnboundMarchChange.OptionsColumn.ShowInCustomizationForm = False
        colUnboundSeptemberChange.OptionsColumn.ShowInCustomizationForm = False

        'Make the Region column read-only.
        colRegion.OptionsColumn.ReadOnly = True

        'Sort data against the Region column.
        colRegion.SortIndex = 0

        'Apply a filter.
        treeList1.ActiveFilterString = "[MarchSales] > 10000"

        'Calculate two total summaries against root nodes.
        colMarchSales.SummaryFooter = DevExpress.XtraTreeList.SummaryItemType.Sum
        colMarchSales.SummaryFooterStrFormat = "Total={0:c0}"
        colMarchSales.AllNodesSummary = False
        colSeptemberSales.SummaryFooter = DevExpress.XtraTreeList.SummaryItemType.Sum
        colSeptemberSales.SummaryFooterStrFormat = "Total={0:c0}"
        colSeptemberSales.AllNodesSummary = False
        treeList1.OptionsView.ShowSummaryFooter = True

        'Use a 'SpinEdit' in-place editor for the 'sales' columns.
        Dim riSpinEdit As RepositoryItemSpinEdit = New RepositoryItemSpinEdit()
        riSpinEdit.DisplayFormat.FormatType = DevExpress.Utils.FormatType.Numeric
        riSpinEdit.DisplayFormat.FormatString = "c0"
        treeList1.RepositoryItems.Add(riSpinEdit)
        colMarchSales.ColumnEdit = riSpinEdit
        colMarchSalesPrev.ColumnEdit = riSpinEdit
        colSeptemberSales.ColumnEdit = riSpinEdit
        colSeptemberSalesPrev.ColumnEdit = riSpinEdit

        'Apply Excel-style formatting: display predefined 'Up Arrow' and 'Down Arrow' icons based on the unbound column values.
        Dim rule1 As TreeListFormatRule = New TreeListFormatRule()
        rule1.Rule = createThreeTrianglesIconSetRule()
        rule1.Column = colUnboundMarchChange
        rule1.ColumnApplyTo = colMarchSales
        Dim rule2 As TreeListFormatRule = New TreeListFormatRule()
        rule2.Rule = createThreeTrianglesIconSetRule()
        rule2.Column = colUnboundSeptemberChange
        rule2.ColumnApplyTo = colSeptemberSales
        treeList1.FormatRules.Add(rule1)
        treeList1.FormatRules.Add(rule2)

        'Do not stretch columns to the treelist width.
        treeList1.OptionsView.AutoWidth = False

        'Locate a node by a value it contains.
        Dim node1 As TreeListNode = treeList1.FindNodeByFieldValue("Region", "North America")
        'Focus and expand this node.
        treeList1.FocusedNode = node1
        node1.Expanded = True

        'Locate a node by its key field value and expand it.
        Dim node2 As TreeListNode = treeList1.FindNodeByKeyID(32) 'Node 'Asia'
        node2.Expand()

        'Calculate the optimal column widths after the treelist is shown.
        Me.BeginInvoke(New MethodInvoker(Sub()
                                             treeList1.BestFitColumns()
                                         End Sub))
    End Sub

    Private Function createThreeTrianglesIconSetRule() As FormatConditionRuleIconSet
        Dim ruleIconSet As FormatConditionRuleIconSet = New FormatConditionRuleIconSet()
        Dim iconSet As FormatConditionIconSet = New FormatConditionIconSet()
        ruleIconSet.IconSet = iconSet
        Dim icon1 As FormatConditionIconSetIcon = New FormatConditionIconSetIcon()
        Dim icon2 As FormatConditionIconSetIcon = New FormatConditionIconSetIcon()
        Dim icon3 As FormatConditionIconSetIcon = New FormatConditionIconSetIcon()
        'Choose predefined icons. 
        icon1.PredefinedName = "Triangles3_3.png"
        icon2.PredefinedName = "Triangles3_2.png"
        icon3.PredefinedName = "Triangles3_1.png"
        'Specify the type of threshold values. 
        iconSet.ValueType = FormatConditionValueType.Number
        'Define ranges to which icons are applied by setting threshold values. 
        icon1.Value = Decimal.MinValue
        icon1.ValueComparison = FormatConditionComparisonType.GreaterOrEqual
        icon2.Value = 0
        icon2.ValueComparison = FormatConditionComparisonType.GreaterOrEqual
        icon3.Value = 0
        icon3.ValueComparison = FormatConditionComparisonType.Greater
        'Add icons to the icon set. 
        iconSet.Icons.Add(icon1)
        iconSet.Icons.Add(icon2)
        iconSet.Icons.Add(icon3)
        Return ruleIconSet
    End Function
End Class

Public Class SalesData
    Shared UniqueID As Integer = 37

    Public Sub New()
        ID = Math.Min(System.Threading.Interlocked.Increment(UniqueID), UniqueID - 1)
    End Sub

    Public Sub New(ByVal id As Integer, ByVal regionId As Integer, ByVal region As String, ByVal marchSales As Decimal, ByVal septemberSales As Decimal, ByVal marchSalesPrev As Decimal, ByVal septermberSalesPrev As Decimal, ByVal marketShare As Double)
        Me.ID = id
        Me.RegionID = regionId
        Me.Region = region
        Me.MarchSales = marchSales
        Me.SeptemberSales = septemberSales
        Me.MarchSalesPrev = marchSalesPrev
        Me.SeptemberSalesPrev = septermberSalesPrev
        Me.MarketShare = marketShare
    End Sub

    Public Property ID As Integer
    Public Property RegionID As Integer
    Public Property Region As String
    Public Property MarchSales As Decimal
    Public Property SeptemberSales As Decimal
    Public Property MarchSalesPrev As Decimal
    Public Property SeptemberSalesPrev As Decimal
    <DisplayFormat(DataFormatString:="p0")>
    Public Property MarketShare As Double
End Class

Public Class SalesDataGenerator
    Public Shared Function CreateData() As List(Of SalesData)
        Dim sales As List(Of SalesData) = New List(Of SalesData)()
        sales.Add(New SalesData(0, -1, "Western Europe", 30540, 33000, 32220, 35500, 0.7))
        sales.Add(New SalesData(1, 0, "Austria", 22000, 28000, 26120, 28500, 0.92))
        sales.Add(New SalesData(2, 0, "France", 23020, 27000, 20120, 29200, 0.51))
        sales.Add(New SalesData(3, 0, "Germany", 30540, 33000, 32220, 35500, 0.93))
        sales.Add(New SalesData(4, 0, "Spain", 12900, 10300, 14300, 9900, 0.82))
        sales.Add(New SalesData(5, 0, "Switzerland", 9323, 10730, 7244, 9400, 0.14))
        sales.Add(New SalesData(6, 0, "United Kingdom", 14580, 13967, 15200, 16900, 0.91))
        sales.Add(New SalesData(17, -1, "Eastern Europe", 22500, 24580, 21225, 22698, 0.62))
        sales.Add(New SalesData(18, 17, "Belarus", 7315, 18800, 8240, 17480, 0.34))
        sales.Add(New SalesData(19, 17, "Bulgaria", 6300, 2821, 5200, 10880, 0.8))
        sales.Add(New SalesData(20, 17, "Croatia", 4200, 3890, 3880, 4430, 0.29))
        sales.Add(New SalesData(21, 17, "Russia", 22500, 24580, 21225, 22698, 0.85))
        sales.Add(New SalesData(26, -1, "North America", 31400, 32800, 30300, 31940, 0.84))
        sales.Add(New SalesData(27, 26, "USA", 31400, 32800, 30300, 31940, 0.87))
        sales.Add(New SalesData(28, 26, "Canada", 25390, 27000, 5200, 29880, 0.64))
        sales.Add(New SalesData(29, -1, "South America", 16380, 17590, 15400, 16680, 0.32))
        sales.Add(New SalesData(30, 29, "Argentina", 16380, 17590, 15400, 16680, 0.88))
        sales.Add(New SalesData(31, 29, "Brazil", 4560, 9480, 3900, 6100, 0.1))
        sales.Add(New SalesData(32, -1, "Asia", 20388, 22547, 22500, 25756, 0.52))
        sales.Add(New SalesData(34, 32, "India", 4642, 5320, 4200, 6470, 0.44))
        sales.Add(New SalesData(35, 32, "Japan", 9457, 12859, 8300, 8733, 0.7))
        sales.Add(New SalesData(36, 32, "China", 20388, 22547, 22500, 25756, 0.82))
        Return sales
    End Function
End Class

using DevExpress.XtraTreeList;
using DevExpress.XtraTreeList.Nodes;

public class MyNode : TreeListNode {
   protected int heightCore;
   // using the inherited constructor to initialize the node
   // and assigning the default value to the Height property
   public MyNode(int id, TreeListNodes owner) : base(id, owner) {
      this.heightCore = -1;
   }
   // specifies the height of an individual node
   public int Height {
      get { return heightCore; }
      set {
         if(value < -1) return;
         if(value > -1 && value < 6) value = 6;
         if(Height != value) {
            heightCore = value;
            if(TreeList != null)
               TreeList.LayoutChanged();
         }
      }
   }
}
public class MyTreeList : TreeList {
   public MyTreeList() {
      // disabling automatic node height calculations
      this.OptionsBehavior.AutoNodeHeight = false;
   }
   // overriding the CreateNode method to use custom nodes
   protected override TreeListNode CreateNode(int nodeID, TreeListNodes owner, object tag) {
      return new MyNode(nodeID, owner);
   }
   // overriding the method that calculated the height of a node
   // assigning the height of the processed node as specified by its Height property
   protected override void RaiseCalcNodeHeight(TreeListNode node, ref int nodeHeight) {
      MyNode _myNode = node as MyNode;
      if(_myNode != null) {
         nodeHeight = _myNode.Height;
      }
      else base.RaiseCalcNodeHeight(node, ref nodeHeight);
   }
}

Imports DevExpress.XtraTreeList
Imports DevExpress.XtraTreeList.Nodes

Public Class MyNode
   Inherits TreeListNode
   Protected HeightCore As Integer
   ' using the inherited constructor to initialize the node
   ' and assigning the default value to the Height property
   Public Sub New(ByVal id As Integer, ByVal owner As TreeListNodes)
      MyBase.New(id, owner)
      Me.HeightCore = -1
   End Sub
   ' specifies the height of an individual node
   Public Property Height() As Integer
      Get
         Return HeightCore
      End Get

      Set(ByVal Value As Integer)
         If Value < -1 Then Return
         If Value > -1 And Value < 6 Then Value = 6
         If Height <> Value Then
            HeightCore = Value
            If Not Tree List Is Nothing Then TreeList.LayoutChanged()
         End If
      End Set
   End Property
End Class

Public Class MyTreeList
   Inherits TreeList
   Public Sub New()
      ' disabling automatic node height calculations
      Me.OptionsBehavior.AutoNodeHeight = False
   End Sub
   ' overriding the CreateNode method to use custom nodes
   Protected Overrides Function CreateNode(ByVal nodeID As Integer, _
     ByVal owner As TreeListNodes, ByVal tag As Object) As TreeListNode
      Return New MyNode(nodeID, owner)
   End Function
   ' overriding the method that calculated the height of a node
   ' assigning the height of the processed node as specified by its Height property
   Protected Overrides Sub RaiseCalcNodeHeight(ByVal node As TreeListNode, _
     ByRef nodeHeight As Integer)
      Dim _myNode As MyNode = node
      If Not _myNode Is Nothing Then
         nodeHeight = _myNode.Height
      Else
         MyBase.RaiseCalcNodeHeight(node, nodeHeight)
      End If
   End Sub
End Class