C#.NET IDataReader扩展 ToList/Get

 

  
    

   
     
   
     using
   
      System;

   
     using
   
      System.Collections.Generic;

   
     using
   
      System.Linq;

   
     using
   
      System.Text;

   
     using
   
      System.Reflection;

   
     using
   
      System.Data;

   
     using
   
      System.Data.Common;

   
     using
   
      System.Web.Script.Serialization;

   
     using
   
      System.IO;

   
     using
   
      System.Security.Cryptography;


   
     namespace
   
      Pub.Class {
 
   
     public
   
      
   
     static
   
      
   
     class
   
      IDataReaderExtensions {

 
   
     public
   
      
   
     static
   
      List
   
     <
   
     TResult
   
     >
   
      ToList
   
     <
   
     TResult
   
     >
   
     (
   
     this
   
      IDataReader dr) 
   
     where
   
      TResult : 
   
     class
   
     ,
   
     new
   
     () { 
 List
   
     <
   
     TResult
   
     >
   
      list
   
     =
   
      
   
     new
   
      List
   
     <
   
     TResult
   
     >
   
     ();
 
   
     if
   
      (dr 
   
     ==
   
      
   
     null
   
     ) 
   
     return
   
      list;
 
   
     int
   
      len 
   
     =
   
      dr.FieldCount;

 
   
     while
   
      (dr.Read()) { 
 TResult info 
   
     =
   
      
   
     new
   
      TResult();
 
   
     for
   
      (
   
     int
   
      j 
   
     =
   
      
   
     0
   
     ; j 
   
     <
   
      len; j
   
     ++
   
     ) {
 
   
     if
   
      (dr[j] 
   
     ==
   
      
   
     null
   
      
   
     ||
   
      
   
     string
   
     .IsNullOrEmpty(dr[j].ToString())) 
   
     continue
   
     ;
 System.Reflection.PropertyInfo pi 
   
     =
   
      info.GetType().GetProperty(dr.GetName(j).Trim());
 pi.SetValue(info, dr[j], 
   
     null
   
     );
 }
 list.Add(info);
 }
 dr.Close(); dr.Dispose(); dr 
   
     =
   
      
   
     null
   
     ;
 
   
     return
   
      list;
 } 

 
   
     public
   
      
   
     static
   
      T Get
   
     <
   
     T
   
     >
   
     (
   
     this
   
      IDataReader reader, 
   
     string
   
      field) {
 
   
     return
   
      reader.Get
   
     <
   
     T
   
     >
   
     (field, 
   
     default
   
     (T));
 }
 
   
     public
   
      
   
     static
   
      T Get
   
     <
   
     T
   
     >
   
     (
   
     this
   
      IDataReader reader, 
   
     string
   
      field, T defaultValue) {
 var value 
   
     =
   
      reader[field];
 
   
     if
   
     (value 
   
     ==
   
      DBNull.Value) 
   
     return
   
      defaultValue;
 
   
     return
   
      value.ConvertTo
   
     <
   
     T
   
     >
   
     (defaultValue);
 }

 } 
}

  
    

 

调用实例：

  
    

   
     
   
      
   
     public
   
      
   
     virtual
   
      IList
   
     <
   
     EC_Type
   
     >
   
      SelectListByAll(
   
     string
   
      order, 
   
     string
   
      fieldList, 
   
     bool
   
      useCache) {
 
   
     string
   
      cacheKey 
   
     =
   
      
   
     string
   
     .Format(
   
     "
   
     EC_TypeCache_SelectListByAll_{0}_{1}
   
     "
   
     , order, fieldList); IList
   
     <
   
     EC_Type
   
     >
   
      list 
   
     =
   
      
   
     null
   
     ;
 
   
     if
   
      (useCache) {
 list 
   
     =
   
      (IList
   
     <
   
     EC_Type
   
     >
   
     )Cache2.Get(cacheKey);
 
   
     if
   
      (list 
   
     !=
   
      
   
     null
   
     ) 
   
     return
   
      list;
 }

 DbParameter[] dbParams 
   
     =
   
      {
 Data.MakeInParam(
   
     "
   
     @Fields
   
     "
   
     , (DbType)SqlDbType.VarChar, 
   
     1000
   
     , fieldList),
 Data.MakeInParam(
   
     "
   
     @Order
   
     "
   
     , (DbType)SqlDbType.VarChar, 
   
     100
   
     , order),
 };
 list 
   
     =
   
      Data.GetDbDataReader(
   
     "
   
     EC_Type_SelectListByAll
   
     "
   
     , dbParams).ToList
   
     <
   
     EC_Type
   
     >
   
     ();
 
   
     if
   
      (useCache) Cache2.Insert(cacheKey, list, cacheSeconds);
 
   
     return
   
      list;
 }