How to: populate TreeView control from a database in VB.NET

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How to populate TreeView control from a database in VB.NET

Find Node in TreeView

You need Treeview control, one TextBox control and one Button. The TextBox control you are using for the name of the searched Treeview node. Into the Button write the code bellow:

Try
        Dim node1() As TreeNode = TreeView1.Nodes(0).Nodes.Find(Text1.Text, True)
        Dim i As Integer = 0

        For i = 0 To node1.Length
            TreeView1.SelectedNode = node1(i)
        Next i
    Catch
    End Try

Determine which Treeview node was clicked

In my example to determine which Treeview node was clicked i will use the both, MsgBox and TextBox.
We are using EventArg object to get the clicked node object.
MsgBox

Private Sub TreeView1_AfterSelect(ByVal sender As System.Object, _
ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterSelect
   
   MsgBox.Show(e.Node.Text)
End Sub

TextBox

Private Sub TreeView1_AfterSelect(ByVal sender As System.Object, _
ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterSelect
   
   TextBox1.Text = e.Node.Text
End Sub
 

Display images in a tree view

 You have to set the TreeView control's ImageList property to the existing ImageList control.
These properties can be set in the designer with the Properties window, or in code.

TreeView1.ImageList = ImageList1

TreeView1.SelectedNode.ImageIndex = 0
TreeView1.SelectedNode.SelectedImageIndex = 1 

Removes currently selected node, or root if nothing is selected

TreeView1.Nodes.Remove(TreeView1.SelectedNode)
' Clears all nodes.
TreeView1.Nodes.Clear()

Adds new node as a child node of the currently selected node

If you want to add a new node as a child node of some selected node you have to write the code bellow:

Dim newNode As TreeNode = New TreeNode("Child node")
TreeView1.SelectedNode.Nodes.Add(newNode)