TreeView Structure in Excel VBA

TreeView is extreamly useful in specific cases but it can be bit tricky sometimes to implement. 

Last Few days I was working on a TreeView Structure and thought I will share the knowledge I gained... 

This post takes you through the basic operations to create and operate a TreeView. It will be like the Folder tree window of the windows explorer.  Moreover, you can have it dynamically updated based on the data in excel....

Here we go..

Idea was to populate the tree completly on the fly from the data defined in the sheet. change the structure and content in the sheet and the TreeView gets updated automatically...

 

1. Get the additional control for the TreeView: 

Get to the VBA Window (Press <ALT+F11>, 

Right Click on the ToolBox Window and 

Select Additional Controls... 

Browse through the window and 

select "Microsoft TreeView Control ...." and "Microsoft ImageList Control ....". 

Now these two items would have come in your TooBox. 

Select and place it on the Form and start working. 

2. Name the Tree: 

I have changed the name of the tree to TV from the default TreeView1. 

Hereon, I will use TV for that item. 

3. Build the Tree up: 

You build tree by adding nodes. You can add a node as a Child or a Parent etc.. 

I like to use the relationship - Child. Basically, each node has a 

..... Key (like the name of controls), 

..... Text (like the Caption of controls), 

..... Index (the ListIndex of a ListBox) 

3.1 Adding Node 

You create each node in relation to another. 

TV.Nodes.Add(Relative:="ThekeyofParent", Relationship:=tvwChild, Key:="NewKey", Text:="New Text") 

The base Node can be added as.. 

TV.Nodes.Add( , , "Key001", "The Base") 

The Next Node can be added as.. 

TV.Nodes.Add("Key001", tvwChild, "Key011", "The First Child") 

3.2 Removing Node 

Remove the Node by refering to the Key or the Index of the item. 

TV.Nodes.Remove(Key) TV.Nodes.Remove

3.3 Clear the Nodes 

TV.Nodes.Clear 

4. Usual properties of Nodes: 

You can refer to a node with its Key or Index. 

..... Key   > TV.Nodes(i).Key 

..... Text   > TV.Nodes(i).Text  or simply  TV.Nodes(i) 

..... Index > TV.Nodes(key).Index 

' Gives the Key of the Node. TV.Nodes(key).Index 

' Gives the Index of the the Node. TV.Nodes(key).children 

' Gives the No of children it has. etc... 

 Its safe to use Int(i) and str(Key) when you are using other variable to refer to index or key. 

5. Nodes Handling: 

Defining the variable for assigning Nodes 

Dim xNode As MSComctlLib.Node 

Usual ways of assigning a node to the variable.. 

Set xNode = TV.Nodes(i) 

Set xNode = TV.Nodes(key) 

Set xNode = TV.SelectedItem 

Get a parent Node or Child Node and cycle through the Nodes... 

To assign xNode to the Parent of the selected item.. 

Set xNode = TV.SelectedItem.Parent 

To assign xNode to the First Child of the selected item.. 

Set xNode = TV.SelectedItem.Child 

To assign xNode to the Parent of the item.. 

Set xNode = xNode.Parent 

To assign xNode to the First Child of the item.. 

Set xNode = xNode.Child 

To assign xNode to the Next item of the same level and same parent 

Set xNode = xNode.Next 

To assign xNode to the First item of the same level and same parent 

Set xNode = xNode.FirstSibling 

To assign xNode to the Last item of the same level and same parent 

Set xNode = xNode.LastSibling 

Remember to Check the node existance before start using it.. 

Check if Node is selected or assigned properly.. 

If Node Is Nothing Then 

   MsgBox "Node not Selected or nonexistant!" 

   Exit Sub 

End If 

Further Reading : http://puremis.net/excel/code/080.shtml .