Combination number

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Diagnostics;
using System.Runtime.CompilerServices;

namespace Combinations
{
    public partial class Form1 : Form
    {

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {

            int lenghtNumber = 11;
            int[] valueToReturn = new int[lenghtNumber];
            generateAllBinary(lenghtNumber, valueToReturn, 0);
        }

        static void generateAllBinary(int lenghtNumber, int [] recursiveArray, int i)
        {

            if (i == lenghtNumber)
            {
                printResult(recursiveArray, lenghtNumber);
                return;
            }


            recursiveArray[i] = 1;
            generateAllBinary(lenghtNumber, recursiveArray, i + 1);


            recursiveArray[i] = 2;
            generateAllBinary(lenghtNumber, recursiveArray, i + 1);

        }

        static void printResult(int[] returningArray, int lenghtNumber)
        {



            string stringToAdd = "";
            for (int i = 0; i < lenghtNumber; i++)
            {
                stringToAdd += returningArray[i];
            }

            Debug.WriteLine(stringToAdd);
        }

    }
}