Working with TreeView in VB.NET

In this article you will how to create and work with an tree view in VB.NET.
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A tree view is a graphical user interface element that present a hierarchical view of information. Each item can have a number of subitems. You can customize the tree, by choosing the text font, icons, connector types, spacing and other properties.

Here I take a example to explain the TreeView control in VB.NET in this example you will see how to create a TreeView and how to create a pop-up menu on right-click of every node and child node to delete the node.

Example of TreeView

Code to write in AssemblyInfo class(AssemblyInfo.vb)

Imports System
Imports System.Reflection
Imports System.Runtime.InteropServices
 
<Assembly: AssemblyTitle("")>
<Assembly: AssemblyDescription("")>
<Assembly: AssemblyCompany("")>
<Assembly: AssemblyProduct("")>
<Assembly: AssemblyCopyright("")>
<Assembly: AssemblyTrademark("")>

<Assembly: CLSCompliant(True)>
<Assembly: Guid("CE6847FE-1A5A-406C-B81F-736B3E7867B0")>
<Assembly: AssemblyVersion("1.0.*")>

Code to write in Main Form(Form1.vb)

Public Class Form1
    Inherits System.Windows.Forms.Form
 
#Region " Windows code "
 
    Public Sub New()
        MyBase.New()
        InitializeComponent()
    End Sub
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then

            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)

    End Sub
 
    Private components As System.ComponentModel.IContainer
 
    Friend WithEvents Trees As System.Windows.Forms.ImageList
    Friend WithEvents Orgn As System.Windows.Forms.TreeView
    Friend WithEvents Buss As System.Windows.Forms.ContextMenu
    Friend WithEvents Group As System.Windows.Forms.ContextMenu
    Friend WithEvents Names As System.Windows.Forms.ContextMenu
    Friend WithEvents BussDelete As System.Windows.Forms.MenuItem
    Friend WithEvents GroupDelete As System.Windows.Forms.MenuItem
    Friend WithEvents NamesDelete As System.Windows.Forms.MenuItem
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.components = New System.ComponentModel.Container()
        Me.Orgn = New System.Windows.Forms.TreeView()
        Me.Trees = New System.Windows.Forms.ImageList(Me.components)
        Me.Buss = New System.Windows.Forms.ContextMenu()
        Me.BussDelete = New System.Windows.Forms.MenuItem()
        Me.Group = New System.Windows.Forms.ContextMenu()
        Me.GroupDelete = New System.Windows.Forms.MenuItem()
        Me.Names = New System.Windows.Forms.ContextMenu()
        Me.NamesDelete = New System.Windows.Forms.MenuItem()
        Me.SuspendLayout()
       
        Me.Orgn.Dock = System.Windows.Forms.DockStyle.Fill
        Me.Orgn.Location = New System.Drawing.Point(0, 0)
        Me.Orgn.Name = "Orgn"
        Me.Orgn.Size = New System.Drawing.Size(260, 300)
        Me.Orgn.TabIndex = 0
        Me.Trees.ColorDepth = System.Windows.Forms.ColorDepth.Depth8Bit
        Me.Trees.ImageSize = New System.Drawing.Size(14, 14)
        Me.Trees.TransparentColor = System.Drawing.Color.Transparent
        Me.Buss.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.BussDelete})
        Me.BussDelete.Index = 0
        Me.BussDelete.Text = "Delete"

        Me.Group.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.GroupDelete})
        Me.GroupDelete.Index = 0
        Me.GroupDelete.Text = "Delete"
        Me.Names.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.NamesDelete})
        Me.NamesDelete.Index = 0
        Me.NamesDelete.Text = "Delete"
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(260, 300)
        Me.Controls.Add(Me.Orgn)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)
    End Sub
#End Region

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Const Bussines As Integer = 0
        Const GroupsAll As Integer = 2
        Const AllNames As Integer = 3
 
        Dim BussinesV As TreeNode
        Dim group As TreeNode
        Dim PersonV As TreeNode
        BussinesV = AddTreeViewNode(Orgn.Nodes, "Export", Bussines, New BussinesVData("Export"))
        group = AddTreeViewNode(BussinesV.Nodes, "Manager", GroupsAll, New GroupData("Manager"))
        PersonV = AddTreeViewNode(group.Nodes, "Manish", AllNames, New PersonVData("Manish"))
        PersonV.EnsureVisible()
        group = AddTreeViewNode(BussinesV.Nodes, "Worker", GroupsAll, New GroupData("Worker"))
        PersonV = AddTreeViewNode(group.Nodes, "Tewatia", AllNames, New PersonVData("Tewatia"))
        PersonV.EnsureVisible()
    End Sub
 
    Private Function AddTreeViewNode(ByVal parent_nodes As TreeNodeCollection, ByVal text As String, ByVal image_index As Integer, Optional ByVal tag_object As
Object
= Nothing) As TreeNode
        Dim new_node As TreeNode = parent_nodes.Add(text)
        new_node.ImageIndex = image_index
        new_node.SelectedImageIndex = image_index
        new_node.Tag = tag_object
        Return new_node
    End Function

    Private Sub BussDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BussDelete.Click
        Orgn.SelectedNode.Remove()
    End Sub

    Private Sub GroupDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles GroupDelete.Click
        Orgn.SelectedNode.Remove()
    End Sub

    Private Sub NamesDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles NamesDelete.Click
        Orgn.SelectedNode.Remove()
    End Sub

    Private Sub Orgn_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Orgn.MouseDown
        If e.Button = MouseButtons.Right Then

            Dim node_here As TreeNode = Orgn.GetNodeAt(e.X, e.Y)
            Orgn.SelectedNode = node_here
            If node_here Is Nothing Then Exit Sub
            If TypeOf node_here.Tag Is BussinesVData Then
                Buss.Show(Orgn, New Point(e.X, e.Y))
            ElseIf TypeOf node_here.Tag Is GroupData Then
                Group.Show(Orgn, New Point(e.X, e.Y))
            ElseIf TypeOf node_here.Tag Is PersonVData Then
                Names.Show(Orgn, New Point(e.X, e.Y))
            End If
        End If
    End Sub
End Class 

Public Class BussinesVData
    Public Name As String
    Public Sub New(ByVal new_name As String)
        Name = new_name
    End Sub
End Class 

Public Class GroupData
    Public Name As String
    Public Projects As Collection
    Public Sub New(ByVal new_name As String, ByVal ParamArray project_names() As String)
        Name = new_name
        Projects = New Collection
        For i As Integer = 0 To project_names.GetUpperBound(0)
            Projects.Add(project_names(i))
        Next i
    End Sub
End Class 

Public Class PersonVData
    Public Name As String
    Public Projects As Collection
    Public Sub New(ByVal new_name As String, ByVal ParamArray project_names() As String)
        Name = new_name
        Projects = New Collection
        For i As Integer = 0 To project_names.GetUpperBound(0)
            Projects.Add(project_names(i))
        Next i
    End Sub
End Class

Output of the above code

tree1.gif
 

Conclusion

I hope this article helps you understand the TreeView control in VB.NET.

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