Recursive scan skipping over accessible files and folders

[Peter Porter]

Please skip to the last reply.

Below my code works fine when I choose a folder with no restrictions, but when I want to log unrestricted files of the entire C drive I get:

UnauthorizedAccessException was unhandled by user code

Access to the path 'C:\$RECYCLE.BIN\S-1-5-18\' is denied.

How can I get around this, catching this exception so my app doesn't crash on Recycle.Bin, but skips over it as well as other restricted folders, restricted subfolders, and restricted files?

Option Strict On

Imports System.IO

Public Class Form1

    Private Dir As String
    Dim FileExt As String
    Dim FilePath As String
    Dim Filename As String
    Dim Items As New List(Of ListViewItem)
    Dim Item As ListViewItem
    Dim i2 As Integer = 0
    Dim message As String


    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.CenterToScreen()
    End Sub


    Private Sub Form1_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Resize
        Dim height As Integer = Me.Height
        If WindowState = FormWindowState.Maximized Then
            Me.Width = SystemInformation.VirtualScreen.Width
            Me.Height = height
            ListView1.Width = Me.Width - 40
            ListView1.Height = Me.Height - 130
        Else
        End If
        Me.CenterToScreen()
    End Sub


    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        ListView1.Items.Clear()
        Items.Clear()
        Dim i As Integer = 0
        Dir = New String(CType(FolderBrowserDialog1.SelectedPath, Char()))
        If (FolderBrowserDialog1.ShowDialog() = DialogResult.OK) Then
            Dir = New String(CType(FolderBrowserDialog1.SelectedPath, Char()))
            Label1.Text = Dir
            ListView1.Items.Clear()
        End If
        BackgroundWorker1.RunWorkerAsync()
    End Sub


    'label2 delegate
    Delegate Sub SetLabelTextInvoker(ByVal label As Label, ByVal Text As String)

    Sub SetLabelText(ByVal Label As Label, ByVal Text As String)
        If Label2.InvokeRequired = True Then
            Label2.Invoke(New SetLabelTextInvoker(AddressOf SetLabelText), Label, Text)
        Else
            Label2.Text = Text
        End If
    End Sub


    Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
        For i As Integer = 0 To i
            For Each files As String In Directory.EnumerateFiles(Dir, "*.*", SearchOption.AllDirectories)

                FileExt = New String(CType(IO.Path.GetExtension(files.ToLower), Char()))
                FilePath = New String(CType(IO.Path.GetDirectoryName(files), Char()))
                Filename = New String(CType(IO.Path.GetFileNameWithoutExtension(files), Char()))

                Dim maxThreads As String = Nothing
                Dim randomc As String

                If maxThreads Is Nothing Then
                    Dim fExt As String = StrConv(FileExt, VbStrConv.ProperCase)
                    randomc = fExt.Trim(CChar(".")).ToUpper & " "
                    If randomc = " " Then
                        randomc = "Unknown"
                    Else
                    End If
                    maxThreads = randomc
                End If

                Dim sizeInBytes As System.IO.FileInfo = My.Computer.FileSystem.GetFileInfo(files)

                Dim separators() As String = {"*", ","}
                Dim filesize As String = CStr(sizeInBytes.Length / 1024)
                Dim input As String() = filesize.Split(separators, StringSplitOptions.RemoveEmptyEntries)
                filesize = input(0)

                Item = New ListViewItem
                Item.Text = Filename & FileExt
                Item.SubItems.Add(maxThreads)
                Item.SubItems.Add(filesize & " KB")
                Item.SubItems.Add(FilePath)

                Items.Add(Item)

                BackgroundWorker1.ReportProgress(i)

                i2 = i
                i = i + 1
                If i = 1 Then
                    SetLabelText(Label2, CStr(i) + " file")
                Else
                    SetLabelText(Label2, CStr(i) + " files")
                End If
            Next

            If i > i2 Then
                If i = 1 Then
                    message = "done"
                    BackgroundWorker1.ReportProgress(i)
                    i = 0
                Else
                    message = "done"
                    BackgroundWorker1.ReportProgress(i)
                    i = 0
                End If
            Else
            End If
        Next
    End Sub


    Private Sub BackgroundWorker1_ProgressChanged(ByVal sender As Object, ByVal e As System.ComponentModel.ProgressChangedEventArgs) Handles BackgroundWorker1.ProgressChanged
        If message = "done" Then
            ListView1.BeginUpdate()
            ListView1.ListViewItemSorter = Nothing
            ListView1.Items.AddRange(Items.ToArray)
            'ListView1.AutoResizeColumns(ColumnHeaderAutoResizeStyle.ColumnContent)
            ListView1.Sort()
            ListView1.EndUpdate()
            message = ""
        Else
        End If
        Label2.Refresh()
    End Sub

End Class

[jmcilhinney]

You cannot use this:

For Each files As String In Directory.EnumerateFiles(Dir, "*.*", SearchOption.AllDirectories)

You need to build your own recursive file search that gets files and subfolders one level at a time. That way, you can wrap the Directory.GetFiles or Directory.EnumerateFiles call in a Try block and catch any exceptions thrown on that call specifically and still carry on searching more folders.

By the way, how does this make sense:

For i As Integer = 0 To i

[Peter Porter]

jmcilhinney, I've been running on fumes the last few days.

By the way, how does this make sense:

For i As Integer = 0 To i

Don't know what I was thinking when I coded that above.

Anyway, I've slapped together my own recursive search. I knew I had to get the directory first and catch exceptions while it searched for files, just couldn't concentrate while struggling to keep my eyes open.

The code below is sloppy, but it works. I'll clean it up after some rest.

Uses 1 button, 1 label, 2 listboxes and a FolderBrowserDialog.

Imports System.IO

Public Class Form1

    Private Dir As String
    Dim FileExt As String
    Dim FilePath As String
    Dim Filename As String
    Dim Items As New List(Of ListViewItem)
    Dim Item As ListViewItem
    Dim i As Integer = 0
    Dim i2 As Integer = 0
    Dim i3 As Integer = 0
    Dim message As String

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        i2 = 0
        i3 = 0
        Dir = New String(CType(FolderBrowserDialog1.SelectedPath, Char()))

        'FolderBrowserDialog
        If (FolderBrowserDialog1.ShowDialog() = DialogResult.OK) Then
            Dir = New String(CType(FolderBrowserDialog1.SelectedPath, Char()))
            ListBox1.Items.Clear()
            ListBox2.Items.Clear()
        End If

        'Add folders to listbox1
        For Each Folder As String In _
   My.Computer.FileSystem.GetDirectories(Dir)
            ListBox1.Items.Add(Folder)
        Next

        Try
            For Each files As String In Directory.EnumerateFiles(Dir, "*.*", SearchOption.TopDirectoryOnly)
                FileExt = New String(CType(IO.Path.GetExtension(files.ToLower), Char()))
                FilePath = New String(CType(IO.Path.GetDirectoryName(files), Char()))
                Filename = New String(CType(IO.Path.GetFileNameWithoutExtension(files), Char()))
                ListBox2.Items.Add(FilePath)

                Dim maxThreads As String = Nothing
                Dim randomc As String

                If maxThreads Is Nothing Then
                    Dim fExt As String = StrConv(FileExt, VbStrConv.ProperCase)
                    randomc = fExt.Trim(CChar(".")).ToUpper & " "
                    If randomc = " " Then
                        randomc = "Unknown"
                    Else
                    End If
                    maxThreads = randomc
                End If

                Dim sizeInBytes As System.IO.FileInfo = My.Computer.FileSystem.GetFileInfo(files)
                Dim separators() As String = {"*", ","}
                Dim filesize As String = CStr(sizeInBytes.Length / 1024)
                Dim input As String() = filesize.Split(separators, StringSplitOptions.RemoveEmptyEntries)
                filesize = input(0)

                Item = New ListViewItem
                Item.Text = Filename & FileExt
                Item.SubItems.Add(maxThreads)
                Item.SubItems.Add(filesize & " KB")
                Item.SubItems.Add(FilePath)
                Items.Add(Item)

                i3 = i2
                i2 = i2 + 1
                If i2 = 1 Then
                    Label1.Text = CStr(i2) + " file"
                Else
                    Label1.Text = CStr(i2) + " files"
                End If
                Label1.Refresh()
            Next
        Catch ex As Exception
        End Try


        'go through Listbox1's items
        For i = 0 To ListBox1.Items.Count - 1

            Try

                'search each folder in listbox1 for all subfolders and files
                For Each files As String In Directory.EnumerateFiles(CStr(ListBox1.Items(i)), "*.*", SearchOption.AllDirectories)
                    FileExt = New String(CType(IO.Path.GetExtension(files.ToLower), Char()))
                    FilePath = New String(CType(IO.Path.GetDirectoryName(files), Char()))
                    Filename = New String(CType(IO.Path.GetFileNameWithoutExtension(files), Char()))
                    ListBox2.Items.Add(FilePath)

                    Dim maxThreads As String = Nothing
                    Dim randomc As String

                    If maxThreads Is Nothing Then
                        Dim fExt As String = StrConv(FileExt, VbStrConv.ProperCase)
                        randomc = fExt.Trim(CChar(".")).ToUpper & " "
                        If randomc = " " Then
                            randomc = "Unknown"
                        Else
                        End If
                        maxThreads = randomc
                    End If

                    Dim sizeInBytes As System.IO.FileInfo = My.Computer.FileSystem.GetFileInfo(files)
                    Dim separators() As String = {"*", ","}
                    Dim filesize As String = CStr(sizeInBytes.Length / 1024)
                    Dim input As String() = filesize.Split(separators, StringSplitOptions.RemoveEmptyEntries)
                    filesize = input(0)

                    Item = New ListViewItem
                    Item.Text = Filename & FileExt
                    Item.SubItems.Add(maxThreads)
                    Item.SubItems.Add(filesize & " KB")
                    Item.SubItems.Add(FilePath)
                    Items.Add(Item)

                    i3 = i2
                    i2 = i2 + 1
                    If i2 = 1 Then
                        Label1.Text = CStr(i2) + " file"
                    Else
                        Label1.Text = CStr(i2) + " files"
                    End If
                    Label1.Refresh()
                Next
            Catch ex As Exception
            End Try
        Next

    End Sub

    
End Class