.NET ORACLE数据库


     大家好，我在学习.net下oracle数据库查询问题，下面一个方法看不懂，哪位大侠稍微帮忙介绍一下！谢谢
       public static DataSet GetDataByPage_lwp(string StrSql, int PageSize, int PageIndex, out int TotalCount)
        {
            using (OracleConnection conn = new OracleConnection(connectionString))
            {
                using (OracleCommand cmd = new OracleCommand())
                {
                    // OracleConnection conn = new OracleConnection(connectionString);
                    // OracleCommand cmd = new OracleCommand();
                    cmd.Connection = conn;
                    cmd.CommandType = CommandType.StoredProcedure;
                    conn.Open();                    cmd.CommandText = "DWMS_PAGE.sp_Page";//包名
                    cmd.Parameters.Add("p_PageSize", OracleDbType.Int32, 10);//分页大小
                    cmd.Parameters.Add("p_PageNo", OracleDbType.Int32, 10);//页码
                    cmd.Parameters.Add("p_SqlSelec", OracleDbType.Varchar2, 3000);//sql语句
                    cmd.Parameters.Add("p_OutRecordCount", OracleDbType.Int32, 10);//返回得记录总数
                    cmd.Parameters.Add("DataSet", OracleDbType.RefCursor);//返回得记录集                    cmd.Parameters["p_PageSize"].Value = PageSize;
                    cmd.Parameters["p_PageNo"].Value = PageIndex;
                    cmd.Parameters["p_SqlSelec"].Value = StrSql;
                    cmd.Parameters["p_OutRecordCount"].Direction = ParameterDirection.Output;
                    cmd.Parameters["DataSet"].Direction = ParameterDirection.Output;
                    try
                    {                        OracleDataAdapter ODAdapter = new OracleDataAdapter(cmd);
                        DataSet dataset = new DataSet();
                        ODAdapter.Fill(dataset);
                        TotalCount = int.Parse(cmd.Parameters["p_OutRecordCount"].Value.ToString());
                        return dataset;
                    }
                    catch (OracleException e)
                    {
                        //throw(e);
                    }
                    TotalCount = 0;
                    return null;
                }
            }             }