Public Class Form1
 
    Private bgwFertig As Boolean
    Private files As System.Collections.ObjectModel.ReadOnlyCollection(Of _
      String)
 
    'Dim SuchPfad As String
    Dim sFile As String
 
 
 
    Private Sub Button2_Click_1(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button2.Click
 
        'SuchPfad = "Z:\INT\Data\CustomerSolutions\Systems\DE_SY"
 
        Button1.Enabled = False
        files = Nothing
        bgwFertig = False
 
        'Dim sPath As String = My.Settings.SuchPfad
        Dim sPath As String = My.Settings.SuchPfad
 
        Dim sParam As String = "*" & TextBox1.Text & "*.pdf"
 
        bgw.RunWorkerAsync(New String() {sPath, sParam})
 
        While Not bgwFertig
            System.Threading.Thread.Sleep(100)
            Application.DoEvents()
        End While
 
        If files Is Nothing OrElse files.Count = 0 Then
            MsgBox("Nix gefunden")
            Return
        End If
 
        For Each sFile In files
            ' Dateien zeigen
            ListBox1.Items.Add(sFile)
        Next
 
        Button1.Enabled = True
 
    End Sub
 
    Private Sub bgw_DoWork(ByVal sender As Object, ByVal e As _
      System.ComponentModel.DoWorkEventArgs) Handles bgw.DoWork
        files = My.Computer.FileSystem.GetFiles(e.Argument(0), _
        FileIO.SearchOption.SearchAllSubDirectories, e.Argument(1))
    End Sub
 
    Private Sub bgw_RunWorkerCompleted(ByVal sender As Object, ByVal e As _
      System.ComponentModel.RunWorkerCompletedEventArgs) Handles _
      bgw.RunWorkerCompleted
        bgwFertig = True
    End Sub
 
End class

Private Sub bgw_DoWork(ByVal sender As Object, ByVal e As _
      System.ComponentModel.DoWorkEventArgs) Handles bgw.DoWork
        files = My.Computer.FileSystem.GetFiles(e.Argument(0), _
        FileIO.SearchOption.SearchAllSubDirectories, e.Argument(1))
    End Sub