Creating a temporary directory in Windows?

I hack Path.GetTempFileName() to give me a valid, pseudo-random filepath on disk, then delete the file, and create a directory with the same file path.

This avoids the need for checking if the filepath is available in a while or loop, per Chris' comment on Scott Dorman's answer.

public string GetTemporaryDirectory()
{
  string tempFolder = Path.GetTempFileName();
  File.Delete(tempFolder);
  Directory.CreateDirectory(tempFolder);

  return tempFolder;
}

If you truly need a cryptographically secure random name, you may want to adapt Scott's answer to use a while or do loop to keep trying to create a path on disk.

No, there is no equivalent to mkdtemp. The best option is to use a combination of GetTempPath and GetRandomFileName.

You would need code similar to this:

public string GetTemporaryDirectory()
{
   string tempDirectory = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
   Directory.CreateDirectory(tempDirectory);
   return tempDirectory;
}