Recursive DFS in C# that prints a directory tree to the console with tree-style connectors, threading the prefix string down each branch.

csharp-directory-tree-console.cs

var path = @"";
if (!Directory.Exists(path))
{
    throw new ArgumentException("Invalid directory path");
}
PrintFileSystemEntries(path);
return;

void PrintFileSystemEntries(string path)
{
    DFS(new DirectoryWithMeta(path, 0));
}


void DFS(DirectoryWithMeta directory, string prefix = "", bool isLast = true)
{
    var entries = Directory.EnumerateFileSystemEntries(directory.Path).ToList();

    var connector = directory.Level == 0 ? "" : (isLast ? "└── " : "├── ");
    Console.WriteLine($"{prefix}{connector}{directory.Path.Split(Path.DirectorySeparatorChar).Last()}");

    var childPrefix = directory.Level == 0 ? "" : prefix + (isLast ? "    " : "│   ");

    for (int i = 0; i < entries.Count; i++)
    {
        var entry = entries[i];
        bool entryIsLast = i == entries.Count - 1;
        var entryConnector = entryIsLast ? "└── " : "├── ";

        if (File.Exists(entry))
        {
            Console.WriteLine($"{childPrefix}{entryConnector}{entry.Split(Path.DirectorySeparatorChar).Last()}");
        }
        else
        {
            DFS(new DirectoryWithMeta(entry, directory.Level + 1), childPrefix, entryIsLast);
        }
    }
}

record DirectoryWithMeta(string Path, int Level);