Dim directory As String = "C:\daten"
    Dim directoryInfo As New IO.DirectoryInfo(directory)
 
    For Each fi As IO.FileInfo In directoryInfo.GetFiles _
        ("*.txt", IO.SearchOption.TopDirectoryOnly)
 
       Dim filepath As String = fi.FullName
       Dim filename As String = fi.Name
       Dim filecontent As String = IO.File.ReadAllText(fi.FullName)
       '....................
    Next fi