Load files and subfolder with windows icons in treeview

[Radjesh Klauke]

Here's an example to show you how to load a particular folder and load all the files and subfolders with the original Windows icons. Next to that, the tag of the files and folders get the original path.



See the attached example for all the controls used etc.

Imports System.Runtime.InteropServices
Imports System.IO
 
Public Class Form1
 
    Dim rootNode, tNode, tempNode As TreeNode
    Dim icoList As New List(Of Integer)
 
#Region "   ICON DECLARATIONS"
 
    Private Declare Auto Function SHGetFileInfo Lib "shell32.dll" _
            (ByVal pszPath As String, _
             ByVal dwFileAttributes As Integer, _
             ByRef psfi As SHFILEINFO, _
             ByVal cbFileInfo As Integer, _
             ByVal uFlags As Integer) As IntPtr
 
    Private Const SHGFI_ICON = &H100
    Private Const SHGFI_SMALLICON = &H1
    Private Const SHGFI_LARGEICON = &H0    ' Large icon
    Private Const MAX_PATH = 260
    Private nIndex = 0
 
    Private Structure SHFILEINFO
        Public hIcon As IntPtr            ' : icon
        Public iIcon As Integer           ' : icondex
        Public dwAttributes As Integer    ' : SFGAO_ flags
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=260)> _
        Public szDisplayName As String
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=80)> _
        Public szTypeName As String
    End Structure
 
    Private Sub AddImages(ByVal strFileName As String)
        Dim shInfo As SHFILEINFO
        shInfo = New SHFILEINFO()
        shInfo.szDisplayName = New String(vbNullChar, MAX_PATH)
        shInfo.szTypeName = New String(vbNullChar, 80)
        Dim hIcon As IntPtr
        hIcon = SHGetFileInfo(strFileName, 0, shInfo, Marshal.SizeOf(shInfo), SHGFI_ICON Or SHGFI_SMALLICON)
        Dim MyIcon As Drawing.Bitmap
        MyIcon = Drawing.Icon.FromHandle(shInfo.hIcon).ToBitmap
        ImageList1.Images.Add(MyIcon)
        nIndex = nIndex + 1
    End Sub
 
    Sub getIcons(ByVal fnode As TreeNode, ByVal fname As String)
        Dim ico As Icon = Icon.ExtractAssociatedIcon(fname)
        If icoList.Contains(ico.Handle) Then '  if icolist already contains icon handle use index   
            For i As Integer = 0 To icoList.Count
                If icoList(i) = ico.Handle Then
                    fnode.ImageIndex = i
                    fnode.SelectedImageIndex = i
                End If
            Next
        Else '  add to imagalist and icoList   
            icoList.Add(ico.Handle)
            ImageList1.Images.Add(ico)
            fnode.ImageIndex = ImageList1.Images.Count - 1 '    ImageList1 starts at zero - so minus 1   
            fnode.SelectedImageIndex = ImageList1.Images.Count - 1
        End If
    End Sub
 
#End Region
 
#Region "   PROJECT EXPLORER FILES / FOLDERS"
 
    Public Function getFolder(ByVal str As String) 'shorten path   
        Dim i As Integer
        Dim shrtPath As String
        i = str.LastIndexOf("\")
        shrtPath = str.Substring(i + 1)
        Return shrtPath
    End Function
 
    Public Sub load_files_treeview()
        Try
            TreeView1.Nodes.Clear()
            Dim isRoot As String = (ToolStripTextBox1.Text) '   << Path of the folder
            rootNode = TreeView1.Nodes.Add(isRoot)
            rootNode.Tag = isRoot   '   name the node   
 
            For Each dir As String In My.Computer.FileSystem.GetDirectories(isRoot)
                addSubFolder(dir)
            Next
 
            icoList.Add(1)
            icoList.Add(2)
 
            loadFiles(rootNode, isRoot)
 
        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try
    End Sub
 
    Private Sub addSubFolder(ByVal dir As String)
        Application.DoEvents()
        Try
            Dim shrtPath As String
            shrtPath = getFolder(dir)
            tNode = rootNode.Nodes.Add(shrtPath)
            tNode.Tag = dir 'name the node
 
            tempNode = tNode.Nodes.Add("temp") 'add temp node
            tempNode.Tag = ("temp") 'name the node
        Catch ex As Exception
 
            MessageBox.Show(ex.Message.ToString, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End Try
    End Sub
 
    Sub loadFolders(ByVal Tnode As TreeNode, ByVal fPath As String)
        Application.DoEvents()
        For Each folderNode As String In Directory.GetDirectories(fPath)
            Dim shortNode As String
            shortNode = getFolder(folderNode) 'shorten path   
 
            Dim subNode As TreeNode = Tnode.Nodes.Add(shortNode)
            subNode.Tag = folderNode
            subNode.Nodes.Add("temp")
        Next
        loadFiles(Tnode, fPath)
    End Sub
 
    Sub loadFiles(ByVal fnode As TreeNode, ByVal dir As String)
        Application.DoEvents()
        For Each filesNode As String In Directory.GetFiles(dir)
            Dim subFileNode As TreeNode = fnode.Nodes.Add(filesNode)
            subFileNode.Tag = filesNode
            subFileNode.Text = Path.GetFileName(filesNode)
            getIcons(subFileNode, filesNode)
        Next
    End Sub
 
    Private Sub TreeView1_AfterSelect(ByVal sender As System.Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterSelect
        Try
            If TreeView1.SelectedNode.Nodes.Count = 1 & TreeView1.SelectedNode.Nodes(0).Text = "temp" Then
                TreeView1.SelectedNode.Nodes.Clear() 'if only temp node exists, delete it   
            Else
                TreeView1.SelectedNode.Nodes.Clear() 'delete temp node   
                loadFolders(TreeView1.SelectedNode, TreeView1.SelectedNode.Tag.ToString)
            End If
            If TreeView1.SelectedNode.ToString.Contains(".") Then
                getIcons(TreeView1.SelectedNode, TreeView1.SelectedNode.Tag)
            End If
        Catch
        End Try
    End Sub
 
    Private Sub TreeView1_BeforeExpand(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeViewCancelEventArgs) Handles TreeView1.BeforeExpand
        Try
            If e.Node.Nodes.Count = 1 Then
                If e.Node.Nodes(0).Text.ToString = "temp" Then
                    e.Node.Nodes.Clear()
                    loadFolders(e.Node, e.Node.Tag.ToString)
                End If
            End If
        Catch
        End Try
    End Sub
 
#End Region
 
    '   ACTIONS "OK" > Load the files and (sub)folders
 
    Private Sub ToolStripButton1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ToolStripButton1.Click
        load_files_treeview()
    End Sub
 
    '   ACTION "EXPAND" > Expand the treeview
 
    Private Sub ToolStripButton2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ToolStripButton2.Click
        TreeView1.ExpandAll()
    End Sub
 
    '   ACTION "SORT" > Sort the files and folders asc.
 
    Private Sub ToolStripButton3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ToolStripButton3.Click
        TreeView1.Sort()
    End Sub
 
    '   doubleclick a node and set the tag into the textbox
 
    Private Sub TreeView1_NodeMouseDoubleClick(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeNodeMouseClickEventArgs) Handles TreeView1.NodeMouseDoubleClick
        TextBox1.AppendText(e.Node.Tag & vbNewLine)
    End Sub
End Class

If somone know how to speed things up, whatever, please let me know.
Have fun with it and "happy coding and God bless"