TreeView

The tree view control is used to display a hierarchy of nodes (both parent, child). You can expand and collpase these nodes by clicking them. This control is similar to Windows Explorer which displays a tree view in it's left pane to list all the folders on the hard disk. Below is the image of a Tree View control.

Notable Properties of TreeView 

Bounds: Gets the actual bound of the tree node
Checked: Gets/Sets whether the tree node is checked
FirstNode: Gets the first child tree node
FullPath: Gets the path from the root node to the current node
ImageIndex: Gets/Sets the image list index of the image displayed for a node
Index: Gets the location of the node in the node collection
IsEditing: Gets whether the node can be edited
IsExpaned: Gets whether the node is expaned
IsSelected: Gets whether the node is selected
LastNode: Gets the last child node
NextNode: Gets the next sibling node
NextVisibleNode: Gets the next visible node
NodeFont: Gets/Sets the font for nodes
Nodes: Gets the collection of nodes in the current node
Parent: Gets the parent node of the current node
PrevNode: Gets the previous sibling node
PrevVisibleNode: Gets the previous visible node
TreeView: Gets the node's parent tree view

TreeView Event

Default event of the Tree View control is the AfterSelect event which looks like this in code:

Private Sub TreeView1_AfterSelect(ByVal sender As System.Object, ByVal e As_ System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterSelect End Sub

Working with Tree Views

Drag a Tree View control on to a form and to add nodes to it select the nodes property in the properties window, which displays the TreeNode editor as shown below.

To start adding nodes, you should click the Add Root button, which adds a top-level node. To add child nodes to that node, you should select that node and use the Add Child button. To set text for a node, select the node and set it's text in the textbox as shown in the image above.

Assuming you added some nodes to the tree view, drag two Labels (Label1, Label2) from the toolbox on to the form. The following code displays the node you select on Label2 and the path to that node on Label1. The code looks like this:

Public Class Form12 Inherits System.Windows.Forms.Form #Region " Windows Form Designer generated code " #End Region Private Sub TreeView1_AfterSelect(ByVal sender As System.Object, ByVal e As_ System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterSelect Label1.Text = "You are here->" & " " & e.Node.FullPath 'displaying the path of the selected node Label2.Text = "Current node selected:" & " " & e.Node.Text 'displaying the selected node End Sub End Class

The image below displays sample output from above code.