Rename a directory or file name to lower case with C#

Introduction

As the title suggests, at first I thought it is an easy task. I mean to rename a file/directory from uppercase or any case to lower case form, how hard can that be?

Obviously I am wrong, it is not very difficult but not very trivial either. So here I am ...

Background 

The first approach I come up with (I think a lot of us will do):

DirectoryInfo _dirInfo = new DirectoryInfo("Your Path");
_dirInfo.MoveTo( _dirInfo.Fullname.ToLower() ); 

Voila, I think I am done then, when I run the program, I get an Exception.

The source and destination path must be different. That make sense, as I only change the directory name to its lower case form.

So to overcome this problem, I revise the MoveTo method of the DirectoryInfo class and come up with the following:

1. If I can't change to lower case, how about I append something to the end?
2. Use the newly created path from (1) and re-instantiate DirectoryInfo.
3. Use (2) to call MoveTo again and obtain the result.

static DirectoryInfo RenameDirectoryToLower(DirectoryInfo dirInfo)
{
  string strLower = dirInfo.FullName.ToLower();
  // (1)
  string strTmpName = dirInfo.FullName + "_temp";
  dirInfo.MoveTo(strTmpName);
  // (2)
  dirInfo = new DirectoryInfo(strTmpName);
  dirInfo.MoveTo(strLower);
  // (3)
  return new DirectoryInfo(strLower);
}

A similar approach can be used for renaming a file to its lower case. Since it is a very small program, I just attached the code below:

//
// The full list for the Console application
//
class Program
{
    static void Main(string[] args)
    {
        var _directoryInfo = new DirectoryInfo(@"C:\testpath");
        ParseDirectory(_directoryInfo);
        Console.ReadLine();
    }
    static void ParseDirectory(DirectoryInfo directoryInfo)
    {
        foreach (var objInfo in directoryInfo.GetDirectories())
        {
            ParseDirectory(RenameDirectoryToLower(objInfo));
        }
        // Files
        foreach (var objFileInfo in directoryInfo.GetFiles())
        {
            RenameFileToLower(objFileInfo);
        }
    }
    static DirectoryInfo RenameDirectoryToLower(DirectoryInfo dirInfo)
    {
        string strLower = dirInfo.FullName.ToLower();
        string strTmpName = dirInfo.FullName + "_temp";
        dirInfo.MoveTo(strTmpName);
        dirInfo = new DirectoryInfo(strTmpName);
        dirInfo.MoveTo(strLower);
        return new DirectoryInfo(strLower);
    }
    static FileInfo RenameFileToLower(FileInfo fileInfo)
    {
        string strLower = fileInfo.FullName.ToLower();
        string strTmpName = fileInfo.FullName + "_temp";
        fileInfo.MoveTo(strTmpName);
        fileInfo = new FileInfo(strTmpName);
        fileInfo.MoveTo(strLower);
        return new FileInfo(strLower);
    }
}

That is it! I have managed to change both the directory and file name into lower case form.

Hope you enjoy this small tip. Happy programming.