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TreeView Explorer Control For Windows Applications

MBTreeView

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 the 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.

  1. It is a simple design that should help you to learn how to use the TreeView control.
  2. Compared with many of the other sample or demo programs available, it loads directories fast!
  3. The program only loads the necessary folders.
  4. Here are only two events and one method that drives the MBTreeViewExplorer control.

Code

The concept for this MBTreeViewExplorer came from Windows Explorer. MBTreeViewExplorer consists of four classes, ShellAPI, Shell Item, ShellDLL, and SystemImageList. I organized the methods MBTreeViewExplorer into layers like the following.

The following method loads all the Folder Nodes for the MBTreeViewExplorer.

Private Sub LoadNodes()
    ' Set Treeview Image List for MBTreeViewExplorer
    SystemImageList.SetTreeViewImageList(MBTreeView, False)
    
    ' New ShellItem to Load Desktop
    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

Using the Code

Code

It is very easy to use 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


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