Рекурсивный поиск файлов

Imports System.Threading
Public Class Form1
    Public trd As Thread
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        System.Windows.Forms.Control.CheckForIllegalCrossThreadCalls = False
    End Sub
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        trd = New Thread(AddressOf ThreadTask)
        trd.IsBackground = True
        trd.Start()
 
       
    End Sub
    Private Sub ThreadTask()
        Dim rnd As New Random()
        Dim searcher As New FindFiles
        For Each s As String In searcher.FindAllFiles("c:\", "*.txt")
                     ListBox1.Items.Add(s)
            Label1.Text = s
            Label2.Text = Label2.Text + 1
            Thread.Sleep(100)
        Next
        ListBox1.Items.Add("Done!")
          End Sub
End Class

Class FindFiles
    Public Function FindAllFiles(ByVal startPath As String, ByVal pattern As String) As List(Of String)
        Dim dir As System.IO.DirectoryInfo = My.Computer.FileSystem.GetDirectoryInfo(startPath)
        Return FindFile(dir, SimplePat2RegEx(pattern))
    End Function
 
    Private Function SimplePat2RegEx(ByVal pattern As String) As String
        Return pattern.Replace("*", "[a-zA-Z0-9]+").Replace("?", "[a-zA-Z0-9]{1,1}")
    End Function
 
    Private Function FindFile(ByVal dir As IO.DirectoryInfo, ByVal pattern As String) As List(Of String)
        Dim out As New List(Of String)
        Try
            For Each f As IO.FileInfo In dir.GetFiles
                If IsMatch(f.FullName, pattern) Then
                    out.Add(f.FullName)
                    Debug.Print(f.FullName)
                End If
            Next
 
            For Each d As IO.DirectoryInfo In dir.GetDirectories
                For Each o As String In FindFile(d, pattern)
                    out.Add(o)
                Next
            Next
        Catch ex As Exception
 
        End Try
 
        Return out
    End Function
 
    Private Function IsMatch(ByVal filename As String, ByVal pattern As String)
        Dim regex As New System.Text.RegularExpressions.Regex(pattern)
        Return regex.IsMatch(filename)
    End Function
End Class

Imports System.IO
Imports System.Threading
 
Public Class Form1
 
Private Sub BtnSearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnSearch.Click
  Dim Mask As String = TxtMask.Text
 
  Call (New Thread(Sub()
    BtnSearch.Invoke(Sub() BtnSearch.Enabled = False)
 
    For Each Root As String In Directory.GetLogicalDrives()
      Search(Root, Mask, Sub(Results As String()) LstResult.Invoke(Sub() LstResult.Items.AddRange(Results)))
    Next Root
 
    BtnSearch.Invoke(Sub() BtnSearch.Enabled = True)
  End Sub)).Start()
End Sub
 
Sub Search(ByVal Folder As String, ByVal Mask As String, ByVal Callback As Action(Of String()))
  Try
    Callback(Directory.GetFiles(Folder, Mask))
  Catch ex As Exception
  End Try
 
  Try
    For Each Folder In Directory.GetDirectories(Folder)
      Search(Folder, Mask, Callback)
    Next Folder
  Catch ex As Exception
  End Try
End Sub
 
Private Sub Form1_FormClosed(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosedEventArgs) Handles MyBase.FormClosed
  End
End Sub
 
End Class

Search(Root, Mask, Sub(Results As String()) LstResult.Invoke(Sub() LstResult.Items.AddRange(Results)))

Dim frm as New Form1'или передать Me параметром в поток
For Each Root As String In Directory.GetLogicalDrives()
      Search(Root, Mask, Sub(Results As String()) LstResult.Invoke(Sub() LstResult.Items.AddRange(Results)))
      frm.Refresh()
Next Root

Directory.GetFiles(Folder, Mask)

Directory.GetFiles(Folder,Microsoft.VisualBasic.FileIO.SearchOption.SearchAllSubDirectories, Mask)