How to get datas from a cloumn in a database(sql) and store in in array?

Using System.Data.SqlClient;
private void Form1_Load(object sender, EventArgs e)
        {
            //Get Count of Records so that we can make array of that member counts 
            
            SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;User Instance=True");
            con.Open();
            SqlCommand comm = new SqlCommand("select count(*) from users",con);
            int count = Convert.ToInt32(comm.ExecuteScalar());
       
            string[] x  = new string[count];
               
            SqlCommand comm2 = new SqlCommand("select * from users",con);
            SqlDataReader reader = comm2.ExecuteReader();

            //Copy Column Data to Array  
            
            int i= 0;
           while (reader.Read())
           {
               x[i] = reader["username"].ToString();
               i++;
           }

           con.Close();



           //Testing The Array 
           for (i = 0; i <= x.Length-1; i++)
           {
               listBox1.Items.Add(x[i]);
           }

        }