// C# Extension Method

// Doc: https://csharp-extension.com/en/method/1002014/fileinfo-createdirectory

​

// @nuget: Z.ExtensionMethods

​

using System;

public class Program

{

    public static void Main()

    {

        string FileName = "folder\\subfolder\\test.txt";

        // C# Extension Method: FileInfo - CreateDirectory

        var dir = FileName.ToFileInfo().CreateDirectory();

        Console.WriteLine(dir.FullName);

    }

}