Why Can't I Inherit IO.Directory?

Question

Why can't I create a class in VB.NET that inherits System.IO.Directory? According to Lutz Roeder, it is not declared as NotInheritable!

I want to create a utility class that adds functionality to the Directory class. For instance, I want to add a Directory.Move function.

Please advise and I will send you a six pack. OK nevermind I'm not sending you anything but if you come to the bar tonight I will hook you up and then beat you in pool.

Thank you Jeff Atwood for editing my post and adding VB.NET tag. No wonder you can't blog anymore! — Josh Stodola, Sep 25 '08 at 20:21

score 11 · Accepted Answer · answered Sep 25 '08 at 20:19

From the Meta Data of .NET

namespace System.IO
{
    // Summary:
    //     Exposes static methods for creating, moving, and enumerating through directories
    //     and subdirectories. This class cannot be inherited.
    [ComVisible(true)]
    public static class Directory

You cannot inherit from a Static Class.

score 5 · Answer 2 · answered Sep 25 '08 at 20:18

5

Are you using ~~C# 3.0~~ VB.NET 2008 -- then you could add an Extension Method

answered Sep 25 '08 at 20:18

Lou Franco

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I know, but what kind of programmer doesn't argue semantics? ;) – CodeRedick Sep 25 '08 at 20:25

score 1 · Answer 3 · answered Sep 25 '08 at 20:19

1

If you use the DirectoryInfo class, you will have access to a MoveTo function.

EDIT: I'll correct myself... The static Directory class already has a Move method.

answered Sep 25 '08 at 20:19

Austin Salonen

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I don't care. I am trying to rename a directory, not move it. – Josh Stodola Sep 25 '08 at 20:24
2

Won't moving the directory to the new name effectively rename it? – Rob Sep 25 '08 at 22:32

score 0 · Answer 4 · answered Sep 25 '08 at 22:29

I'd guess that Reflector isn't picking up the sealed attribute correctly for VB (or perhaps just not displaying it properly). If you look at the IL, it is sealed:

class public abstract auto ansi sealed beforefieldinit Directory

Why Can't I Inherit IO.Directory?

4 Answers4

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