Introduction
What is the MBTreeViewExplorer
? This is a simple TreeView
derived control that uses the Windows Explorer interface. It provides no added functionality aside from the standard TreeView
control methods, properties and events, however it does provide a Shell Item class that can be used to extend this basic example for your own needs and it is also a good starting point for those wanting to get to grips with the system image list and Shell32 programming.
Background
MBTreeViewExplorer
is an explorer that inherits all the properties of a simple TreeView
control. The language used is VB.NET. Parts of the code are based on other CodeProject tutorials and code samples found elsewhere on the Internet. All of the code was written by me but some of the concepts are from other references and books.
What I think is best about this program is:
- It is a simple design that should help you to learn how to use the
TreeView
control.
- Compared with many of the other sample or demo programs available, it loads directories fast!
- The program only loads the necessary folders.
- Here are only two events and one method that drives the
MBTreeViewExplorer
control.
Code
The concept for this MBTreeViewExplorer
came from the Windows Explorer. MBTreeViewExplorer
consists of four classes, ShellAPI, Shell Item, ShellDLL and SystemImageList. I organized the methods of MBTreeViewExplorer
into layers like the following.
The following method loads all the Folder Nodes for the MBTreeViewExplorer
:
- Private Sub LoadNodes()
-
- SystemImageList.SetTreeViewImageList(MBTreeView, False)
-
- Dim m_shDesktop As ShellItem = New ShellItem()
- Dim tvwRoot As TreeNode = New TreeNode()
- tvwRoot.Name = m_shDesktop.Path
- tvwRoot.Text = m_shDesktop.DisplayName
- tvwRoot.ImageIndex = m_shDesktop.IconIndexNormal
- tvwRoot.SelectedImageIndex = m_shDesktop.IconIndexOpen
- tvwRoot.Tag = m_shDesktop
-
- Dim arrChildren As ArrayList = m_shDesktop.GetAllDirectories
- For Each shChild As ShellItem In arrChildren
- Dim tvwChild As TreeNode = New TreeNode()
- tvwChild.Name = shChild.Path
- tvwChild.Text = shChild.DisplayName
- tvwChild.ImageIndex = shChild.IconIndexNormal
- tvwChild.SelectedImageIndex = shChild.IconIndexOpen
- tvwChild.Tag = shChild
- If shChild.IsFolder And shChild.HasSubFolders Then tvwChild.Nodes.Add("PH")
- tvwRoot.Nodes.Add(tvwChild)
- Next
- MBTreeView.Nodes.Clear()
- MBTreeView.Nodes.Add(tvwRoot)
- tvwRoot.Expand()
- End Sub
The following method handles Icons for the
MBTreeViewExplorer
:
- Public Shared Sub SetTreeViewImageList( _
- ByVal treeView As TreeView, _
- ByVal forStateImages As Boolean)
- Initializer()
- Dim wParam As Integer = LVSIL_NORMAL
- If forStateImages Then
- wParam = LVSIL_STATE
- End If
- Dim HR As Integer
- HR = SendMessage(treeView.Handle, _
- TVM_SETIMAGELIST, _
- wParam, _
- m_smImgList)
- End Sub
It is very easy to use the MBTreeViewExplorer
in your application. Simply add the reference of the provided DLL to your application and just drag and drop.
History
MBTreeViewExplorer
Version 1.0