.net反射实例（再次优化后）

来源：互联网发布：java建立一个数组编辑：程序博客网时间：2024/04/29 21:32

以上代码，经过优化后，速度几乎和直接用reader读出来差不多，但没解决第二个问题，model中的属性值还是必须和数据库表中的字段名完全一样，下面是再次改进后的代码：

/// <summary>

/// 分页查询；函数中，存储过程参数含义见接口文档

/// </summary>

/// <param name="table_Name">表或视图名</param>

/// <param name="Fields">字段列表,“*”为全部字段</param>

/// <param name="limit_Condition">where条件（不用带where）</param>

/// <param name="order_By">排序关键字（不用带order by）</param>

/// <param name="order_Direction">查询顺序（升序asc或降序desc）</param>

/// <param name="page_Size">每页显示条数</param>

/// <param name="current_Page">当前页码</param>

/// <returns>返回一个数据集</returns>

public List<Model.Ppt> Select(string table_Name, string Fields, string limit_Condition, string order_By, string order_Direction, int page_Size, int current_Page)

{

SqlParameter[] para = new SqlParameter[7];

para[0] = new SqlParameter("@TableName", table_Name);

para[1] = new SqlParameter("@ReFieldsStr", Fields);

para[2] = new SqlParameter("@OrderString", order_By);

para[3] = new SqlParameter("@OrderDirection", order_Direction);

para[4] = new SqlParameter("@WhereString", limit_Condition);

para[5] = new SqlParameter("@PageSize", page_Size);

para[6] = new SqlParameter("@PageIndex ", current_Page);

List<Model.Ppt> list = new List<Model.Ppt>();

Hashtable hashValue = new Hashtable();

Model.Ppt model = new Model.Ppt();

object temp=new Model.Ppt();

object[] objPptFieldAttribute = null;

int fieldNum = 18;

PropertyInfo[] infos = model.GetType().GetProperties();

string[] field = Fields.Split(',');

using (SqlDataReader reader = SQLHelper.ExecuteReader(conn, CommandType.StoredProcedure, "PROCE_PAGECHANGE", para))

{

while (reader.Read())

{

hashValue = new Hashtable();

temp = new Model.Ppt();

foreach (string fName in field)

{

for (int i = 0; i < fieldNum; i++)

{

if ("*" == fName)

{

objPptFieldAttribute = infos.GetCustomAttributes(typeof(Map.PptFieldAttribute), false);

if (objPptFieldAttribute != null)

{

if (DBNull.Value != reader[infos.Name])

{

hashValue.Add(infos.Name, reader[((Map.PptFieldAttribute)objPptFieldAttribute[0]).FieldName]);

infos.SetValue(temp, hashValue[infos.Name], null);

}

else

{

if (infos.Name == fName)

{

objPptFieldAttribute = infos.GetCustomAttributes(typeof(Map.PptFieldAttribute), false);

if (objPptFieldAttribute != null)

{

if (DBNull.Value != reader[infos.Name])

{

hashValue.Add(infos.Name, reader[((Map.PptFieldAttribute)objPptFieldAttribute[0]).FieldName]);

infos.SetValue(temp, hashValue[infos.Name], null);

}

break;

}

list.Add((Model.Ppt)temp);

}

return list;

}

Model

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Map;

namespace Model
{
public class Ppt : IComparable<Ppt>
{
      //课件Id
      private int _Ppt_Id;
      [PptField("Ppt_Id","int")]
      public int Ppt_Id
      {
         get { return _Ppt_Id; }
         set { _Ppt_Id = value; }
      }
      //课件名
      private string _Ppt_Name;
      [PptField("Ppt_Name", "nvarchar")]
      public string Ppt_Name
      {
         get { return _Ppt_Name; }
         set { _Ppt_Name = value; }
      }
      //作者
      private string _Ppt_Author;
      [PptField("Ppt_Author", "nvarchar")]
      public string Ppt_Author
      {
         get { return _Ppt_Author; }
         set { _Ppt_Author = value; }
      }
      //课件长度
      private string _Ppt_Length;
      [PptField("Ppt_Length", "nvarchar")]
      public string Ppt_Length
      {
         get { return _Ppt_Length; }
         set { _Ppt_Length = value; }
      }
      //所属目录
      private string _Ppt_Catalog;
      [PptField("Ppt_Catalog", "nvarchar")]
      public string Ppt_Catalog
      {
         get { return _Ppt_Catalog; }
         set { _Ppt_Catalog = value; }
      }
      //发布范围
      private string _Ppt_Range;
      [PptField("Ppt_Range", "nvarchar")]
      public string Ppt_Range
      {
         get { return _Ppt_Range; }
         set { _Ppt_Range = value; }
      }
      //描述
      private string _Ppt_Description;
      [PptField("Ppt_Description", "text")]
      public string Ppt_Description
      {
         get { return _Ppt_Description; }
         set { _Ppt_Description = value; }
      }
      //WebExame链接
      private string _Ppt_WebExameLink;
      [PptField("Ppt_WebExameLink", "nvarchar")]
      public string Ppt_WebExameLink
      {
         get { return _Ppt_WebExameLink; }
         set { _Ppt_WebExameLink = value; }
      }

//课件路径
      private string _Ppt_Path;
      [PptField("Ppt_Path", "nvarchar")]
      public string Ppt_Path
      {
         get { return _Ppt_Path; }
         set { _Ppt_Path = value; }
      }
      //题目截图
      private string _Ppt_TopicImage;
      [PptField("Ppt_TopicImage", "nvarchar")]
      public string Ppt_TopicImage
      {
         get { return _Ppt_TopicImage; }
         set { _Ppt_TopicImage = value; }
      }
      //讲师截图
      private string _Ppt_LecImage;
      [PptField("Ppt_LecImage", "nvarchar")]
      public string Ppt_LecImage
      {
         get { return _Ppt_LecImage; }
         set { _Ppt_LecImage = value; }
      }
      //目录截图
      private string _Ppt_CatalogImage;
      [PptField("Ppt_CatalogImage", "nvarchar")]
      public string Ppt_CatalogImage
      {
         get { return _Ppt_CatalogImage; }
         set { _Ppt_CatalogImage = value; }
      }
      //课件顺序
      private int _Ppt_Order;
      [PptField("Ppt_Order", "int")]
      public int Ppt_Order
      {
         get { return _Ppt_Order; }
         set { _Ppt_Order = value; }
      }
      //平均分数
      private int _Ppt_Score;
      [PptField("Ppt_Score", "int")]
      public int Ppt_Score
      {
         get { return _Ppt_Score; }
         set { _Ppt_Score = value; }
      }
      //有效点击数
      private int _Ppt_Click;
      [PptField("Ppt_Click", "int")]
      public int Ppt_Click
      {
         get { return _Ppt_Click; }
         set { _Ppt_Click = value; }
      }

Map:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Map
{
public class PptFieldAttribute:Attribute
{
      private string _FieldName;
      private string _FieldType;

      public PptFieldAttribute(string fieldname,string fieldtype)
      {
         this._FieldName = fieldname;
         this._FieldType = fieldtype;
      }

      /// <summary>
      /// 字段名
      /// </summary>
      public string FieldName
      {
         get { return this._FieldName; }
      }

      /// <summary>
      /// 字段类型
      /// </summary>
      public string FieldType
      {
         get { return this._FieldType; }
         set { this._FieldType = value; }
      }


}
}

本次优化把两个问题都解决了，速度是直接reader的一倍左右，可以接受