学步园

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Reflection;
using Microsoft.ApplicationBlocks.Data;
using System.Data.SqlClient;

public partial class PowerORM : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string strConnection = "Server=127.0.0.1;User ID=sa;Password=qqww;Persist Security Info=True;DataBase=Northwind;";
        string strSQL = "SELECT [CustomerID], [CompanyName], [ContactName] FROM [Customers]";
        IList myList;
        using (SqlDataReader myReader = SqlHelper.ExecuteReader(strConnection, CommandType.Text, strSQL))
        {
            myList = myPowerORM.FillHelper.Fill((new myPowerORM.Customer()).GetType(), myReader);
        }

        Response.Write("<pre>");

        foreach (object o in myList)
        {
            myPowerORM.Customer c = (myPowerORM.Customer)o;

            Response.Write(c.CustomerID+"\t"+c.CompanyName+"\t"+c.ContactNameI+"\n<br>");
        }

        Response.Write("</pre>");


    }
}





namespace myPowerORM
{
    public class Customer
    {
        private string _customerID, _companyName, _contactName;

        [Column("CustomerID")]
        public string CustomerID
        {
            get { return _customerID; }
            set { _customerID = value; }
        }

        [Column("CompanyName")]
        public string CompanyName
        {
            get { return _companyName; }
            set { _companyName = value; }
        }

        [Column("ContactName")]
        public string ContactNameI
        {
            get { return _contactName; }
            set { _contactName = value; }
        }
        public Customer() { }
    }

    [AttributeUsage(AttributeTargets.Property, Inherited = false, AllowMultiple = false)]
    public class ColumnAttribute : Attribute
    {
        private string _columnName = null;

        public string ColumnName
        {
            get { return _columnName; }
        }

        public ColumnAttribute(string columnName)
        {
            _columnName = columnName;
        }
    }


    public class FillHelper
    {
        public static IList Fill(Type rowType, IDataReader reader)
        {
            ArrayList dataList = new ArrayList();
            while (reader.Read())
            {
                object item = Activator.CreateInstance(rowType, false); //使用与指定参数匹配程度最高的构造函数创建指定类型的实例
                foreach (MemberInfo mi in rowType.GetMembers())
                {
                    foreach (ColumnAttribute attr in mi.GetCustomAttributes(typeof(ColumnAttribute), false))
                    {
                        int index = reader.GetOrdinal(attr.ColumnName); //在给定列名称的情况下获取列序号
                        if (index != -1)
                        {
                            if (mi.MemberType == MemberTypes.Field)
                                ((FieldInfo)mi).SetValue(item, reader.GetValue(index));
                            else if (mi.MemberType == MemberTypes.Property)
                                ((PropertyInfo)mi).SetValue(item, reader.GetValue(index), null);
                        }
                    }
                }
                dataList.Add(item);
            }
            return dataList;
        }
        public FillHelper() { }
    }
}