面试常考题DataReader及其优化

          protected void Button1_Click(object sender, EventArgs e)
        {
            List<Person> list = new List<Person>();
            using (SqlConnection conn = new SqlConnection(connectStr))
            {
                SqlCommand cmd = new SqlCommand(sql, conn);
                conn.Open();
                SqlDataReader reader = cmd.ExecuteReader();
                if (reader.HasRows)
                {
                    while (reader.Read())  --在读之前判断是否还有数据
                    {
                        list.Add(new Person() { Id = int.Parse(reader["Id"].ToString()), Name = reader["Name"].ToString(), age = int.Parse(reader["age"].ToString()) });
                    } 
                }
            }
        }

       测试类：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace DataReader
{
    public class Person
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public int age { get; set; }
        public string sex { get; set; }
    }
}