c# - Fill generic list from SqlDataReader

Question

How can I add values that a SqlDataReader returns to a generic List? I have a method where I use SqlDataReader to get CategoryID from a

Answer 1

AS BrokenGlass explained this is the demonstration

SqlConnection connection = null;
        SqlDataReader dr= null;
        SqlCommand cmd = null;
List catID = new List();
        try
        {
            connection = new SqlConnection(connectionString);
            cmd = new SqlCommand("select CategoryID from Categories", connection );

            connection.Open();



            dr = cmd.ExecuteReader();
            while (dr.Read())
            {
                catID.Add(Convert.ToInt32(dr["CategoryID"].ToString()));
            }


        }
        finally
        {
            if (connection  != null)
                connection.Close();
        }
        return catID;

as well as you change the declaration

SqlDataReader reader = null;

to

SqlDataReader dr= null; // Because you are using dr in the code not reader