A few helper functions for assisting with operations on a Directory.

DirInfo.cs

public static List<string> GetFileNamesWithoutExtensionAsList(string dir, string pattern)
{
    if (Directory.Exists(dir))
    {
        return new DirectoryInfo(dir).GetFiles(pattern, SearchOption.TopDirectoryOnly)
            .Select(file => Path.GetFileNameWithoutExtension(file.Name)).ToList();
    }
    return new List<string>();
}

public static IEnumerable<string> GetFileNamesWithoutExtensionAsIEnumerable(string dir, string pattern)
{
    if (Directory.Exists(dir))
    {
        return new DirectoryInfo(dir).GetFiles(pattern, SearchOption.TopDirectoryOnly)
            .Select(file => Path.GetFileNameWithoutExtension(file.Name));
    }
    return new List<string>();
}

public static void CreateDirectory(string dirPath)
{
    if (!Directory.Exists(dirPath))
    {
        Directory.CreateDirectory(dirPath);
    }
}