using System;
using System.Collections.Generic;
using System.Data;
using System.Reflection;


namespace DAL
{
 /// <summary>
 /// 用于給 DataTable和 DataRow擴(kuò)展方法
 /// </summary>
 public static class TableExtensionMethod
 {

  /// <summary>
  /// 功能：
  ///  給DataTable擴(kuò)展了一個(gè)方法，能夠?qū)ataTable中的行轉(zhuǎn)變?yōu)閷?duì)應(yīng)的class對(duì)象，并封裝到List集合中；
  /// </summary>
  /// <typeparam name="T">需要轉(zhuǎn)變成為的class類(lèi)型</typeparam>
  /// <param name="table">傳入的DataTable對(duì)象</param>
  /// <returns>返回一個(gè)封裝了對(duì)應(yīng)class的List集合</returns>
  public static List<T> TableToClass<T>(this DataTable table)
  {
   Type type = typeof(T);
   PropertyInfo[] propArr = type.GetProperties();//獲取所有屬性
   List<T> list = new List<T>();
   DataRowCollection rows = table.Rows;
   int len = rows[0].ItemArray.Length;//獲取第一行的列數(shù)，即class的屬性個(gè)數(shù)
   for (int i = 0; i < rows.Count; i++)
   {
    T t = (T)Activator.CreateInstance(type);
    for (int j = 0; j < len; j++)//這里之所以不使用propArr.Length，是因?yàn)橛行㎝odels的屬性在數(shù)據(jù)表中不存在對(duì)應(yīng)的列
    {
     propArr[j].SetValue(t, rows[i][j]);
    }
    list.Add(t);
    t = default(T);
   }
   return list;
  }

  /// <summary>
  /// 功能：
  ///  DataRow的擴(kuò)展方法；
  ///  能夠?qū)ataRow對(duì)象封裝到泛型對(duì)象中
  /// </summary>
  /// <typeparam name="T">需要轉(zhuǎn)換成為的class類(lèi)型</typeparam>
  /// <param name="row">被轉(zhuǎn)換的行</param>
  /// <returns>封裝了行數(shù)據(jù)的class對(duì)象</returns>
  public static T RowToClass<T>(this DataRow row)
  {
   //Type type = Assembly.Load(classFullName).GetType();
   Type type = typeof(T);
   T t = (T)Activator.CreateInstance(type);
   PropertyInfo[] propArr = type.GetProperties();
   int len = row.ItemArray.Length;
   for (int i = 0; i < len; i++)
   {
    propArr[i].SetValue(t, row[i]);
   }
   return t;
  }

  /// <summary>
  /// 功能：
  ///  DataRowCollection的擴(kuò)展方法；
  ///  能夠?qū)ataRowCollection對(duì)象封裝到泛型List集合中
  /// </summary>
  /// <typeparam name="T"></typeparam>
  /// <param name="rows"></param>
  /// <returns></returns>
  public static List<T> RowToClass<T>(this DataRow row, DataRow[] rowArr)
  {
   Type type = typeof(T);
   PropertyInfo[] propArr = type.GetProperties();
   int len = rowArr[0].ItemArray.Length;//獲取數(shù)據(jù)表第一行的列數(shù)，即屬性個(gè)數(shù)
   List<T> list = new List<T>();
   for (int i = 0; i < rowArr.Length; i++)
   {
    T t = (T)Activator.CreateInstance(type);
    for (int j = 0; j < len; j++)
    {
     propArr[j].SetValue(t, rowArr[i][j]);
    }
    list.Add(t);
    t = default(T);
   }
   return list;
  }
 }
}