CODEWITHSUNDEEP
vb.net
user2658544
user2658544

Reputation: 11

Display all drives, files, and subfolders in treeview

I'm looking for the simplest way to display all drives, files, and subfolders in a treeview. If someone's got a snippet of code to do this that they don't mind sharing I would really appreciate it.

The closest I've gotten was this code I tried using, but it gave me a "IOException was unhandled" error saying "The device is not ready." error at runtime (after about 5-10 sec) on the line below

Dim folders() As String = IO.Directory.GetDirectories(dir)

underneath is the rest of the code

Private Sub Main_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    Dim drives As System.Collections.ObjectModel.ReadOnlyCollection(Of IO.DriveInfo) = My.Computer.FileSystem.Drives
    Dim rootDir As String = String.Empty
    For i As Integer = 0 To drives.Count - 1
        rootDir = drives(i).Name
        TreeView1.Nodes.Add(rootDir)
        PopulateTreeView(rootDir, TreeView1.Nodes(i))
    Next
End Sub

Private Sub PopulateTreeView(ByVal dir As String, ByVal parentNode As TreeNode)
    Dim folder As String = String.Empty
    Try
        Dim folders() As String = IO.Directory.GetDirectories(dir)
        If folders.Length <> 0 Then
            Dim childNode As TreeNode = Nothing
            For Each folder In folders
                childNode = New TreeNode(folder)
                parentNode.Nodes.Add(childNode)
                PopulateTreeView(folder, childNode)
            Next
        End If
    Catch ex As UnauthorizedAccessException
        parentNode.Nodes.Add(folder & ": Access Denied")
    End Try
End Sub

Upvotes: 1

Views: 14748

Answers (1)

Steven Liekens
Steven Liekens

Reputation: 14088

Seems like you're off to a good start. The IOException you receive is most likely caused by your procedure trying to list contents on an empty disc drive, which is obviously impossible.

The fix is simple:

For i As Integer = 0 To drives.Count - 1
    If Not drives(i).IsReady Then
        Continue For
    End If
    rootDir = drives(i).Name
    TreeView1.Nodes.Add(rootDir)
    PopulateTreeView(rootDir, TreeView1.Nodes(i))
Next

Besides that, I recommend not loading folder contents until a node is clicked. Limit the recursive call to 1 level (current directory + content of all its subdirectories). That way, you get the best performance while still being able to determine whether a subdirectory should have the treeview expand button.

Upvotes: 1

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