Option Explicit On
Option Strict On
Option Compare Binary
REM Option Infer Off
 
Imports System
 
Public Class Test
	Public Shared Sub Main()
 
		Dim s As String = "D:\ディレクトリ1\ディレクトリ2\テキストファイル.txt"
		System.Console.WriteLine(new System.IO.DirectoryInfo(System.IO.Path.GetDirectoryName(s)).Name)
 
		REM #2氏の回答後に追記
		REM System.Console.WriteLine(new System.IO.FileInfo(s).Directory.Name)
		REM の方が簡潔な気がする		
 
 
	End Sub
End Class

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