C#

List<uielements> _list = new List<uielements>(){new Dialog1(), new Dialog2(), new Dialog3()};

internal UIElement GiveNavigationItem(int p, Type lastElement)
{
 var result = from o in _list
                             where o.GetType() == lastElement
                             select o; //HERE I NEED THE INDEX AND NOT THE OBJECT ITSELF

 //RESULT SHOULD BE INT32
 return _list[result + p];

}</uielements></uielements>

private void Changing(int[] is, int i)
{
    is[0] = 100;
    i = 100;
}

static void Main()
{
    int[] is = {0, 1, 2, 3, 4};
    int i = 0;
    Console.WriteLine(i); // Writes 0
    Console.WriteLine(is[0]); // Writes 0

    Changing(is, i);
    Console.WriteLine(i); // Still 0.
    Console.WriteLine(is[0]); // Prints 100!
}

// database connection (no parameters)
        public static void DataGridView_Fill(DataGridView data_grid_view, string store_procedure)
        {
            SqlConnection sql_conn = new SqlConnection(connection_string);
            SqlCommand sql_cmd = new SqlCommand();
            sql_cmd.Connection = sql_conn;
            sql_cmd.CommandText = store_procedure;
            sql_cmd.CommandType = CommandType.StoredProcedure;
            sql_conn.Open();
            SqlDataAdapter sql_da = new SqlDataAdapter();
            sql_da.SelectCommand = sql_cmd;
            DataTable dt = new DataTable();
            sql_da.Fill(dt);
            sql_conn.Close();
            data_grid_view.DataSource = dt;
        }