使用ExecuteReader时报错“阅读器关闭时尝试调用Read无效”的解决办法

出现如下绿色字体出错的问题，是由于using使用过后数据库会自动关闭，出了using的作用域后，在调用的时候无法找到信息

form1.cs

        public static SqlDataReader ExecuteReader(string sql, params SqlParameter[] parameters)
        {
            string connStr = ConfigurationManager.ConnectionStrings["ConnStr"].ConnectionString;
            using (SqlConnection conn = new SqlConnection(connStr))
            {
                conn.Open();
                using (SqlCommand cmd = conn.CreateCommand())
                {
                    cmd.CommandText = sql;
                    foreach (SqlParameter parameter in parameters)
                    {
                        cmd.Parameters.Add(parameter);
                    }
                    return cmd.ExecuteReader();
                }                
            }  
        }

DBHelper.cs

        private void button2_Click(object sender, EventArgs e)
        {
            SqlDataReader reader = DBHelper.ExecuteReader("select * from T_Person");
            while (reader.Read ())
            {
                string name = reader.GetString(reader.GetOrdinal("Name"));
                MessageBox.Show(name);
            }
        }

改：将Using去掉，用手动打开open、关闭close，用cmd.ExecuteReader(CommandBehavior.CloseConnection)

form1.cs

public static SqlDataReader ExecuteReader(string sql, params SqlParameter[] parameters)
        {
            string connStr = ConfigurationManager.ConnectionStrings["ConnStr"].ConnectionString;
            SqlConnection conn = new SqlConnection(connStr);
            conn.Open();
            SqlCommand cmd = conn.CreateCommand();
            cmd.CommandText = sql;
            foreach (SqlParameter parameter in parameters)
            {
                cmd.Parameters.Add(parameter);
            }
            return cmd.ExecuteReader(CommandBehavior.CloseConnection);

        }

DBHelper.cs

        private void button2_Click(object sender, EventArgs e)
        {
            SqlDataReader reader = DBHelper.ExecuteReader("select * from T_Person");
            while (reader.Read ())
            {
                string name = reader.GetString(reader.GetOrdinal("Name"));
                MessageBox.Show(name);
            }
        }