利用反射实现通用的DataReader转List、DataReader转实体类

dataReader转list和转model有时候经常用，为了偷懒嘛，少写代码倒是不少，用缓存基本上也可以把性能补过来吧，反正我没有测试过，哪位同仁测试过，大家可以研究研究~~

把整理好的代码贴出来如下：大家可以参考参考   有点乱，注释就没有写了，地球人应该都看得懂，呵呵

  public   static  T ReaderToModel < T > (IDataReader dr)
    {
         try
        {
             using  (dr)
            {
                 if  (dr.Read())
                {
                    List < string >  list  =   new  List < string > (dr.FieldCount);
                     for  ( int  i  =   0 ; i  <  dr.FieldCount; i ++ )
                    {
                        list.Add(dr.GetName(i).ToLower());
                    }
                    T model  =  Activator.CreateInstance < T > ();
                     foreach  (PropertyInfo pi  in  model.GetType().GetProperties(BindingFlags.GetProperty  |  BindingFlags.Public  |  BindingFlags.Instance))
                    {
                         if  (list.Contains(pi.Name.ToLower()))
                        {
                             if  ( ! IsNullOrDBNull(dr[pi.Name]))
                            {
                                pi.SetValue(model, HackType(dr[pi.Name], pi.PropertyType),  null );
                            }
                        }
                    }
                     return  model;
                }
            }
             return   default (T);
        }
         catch  (Exception ex)
        {
             throw  ex;
        }
    }


     public   static  List < T >  ReaderToList < T > (IDataReader dr)
    {
         using  (dr)
        {
            List < string >  field  =   new  List < string > (dr.FieldCount);
             for  ( int  i  =   0 ; i  <  dr.FieldCount; i ++ )
            {
                field.Add(dr.GetName(i).ToLower());
            }
            List < T >  list  =   new  List < T > ();
             while  (dr.Read())
            {
                T model  =  Activator.CreateInstance < T > ();
                 foreach  (PropertyInfo property  in  model.GetType().GetProperties(BindingFlags.GetProperty  |  BindingFlags.Public  |  BindingFlags.Instance))
                {
                     if  (field.Contains(property.Name.ToLower()))
                    {
                         if  ( ! IsNullOrDBNull(dr[property.Name]))
                        {
                            property.SetValue(model, HackType(dr[property.Name], property.PropertyType),  null );
                        }
                    }
                }
                list.Add(model);
            }
             return  list;
        }
    }
    //这个类对可空类型进行判断转换，要不然会报错
     private   static   object  HackType( object  value, Type conversionType)
    {
         if  (conversionType.IsGenericType  &&  conversionType.GetGenericTypeDefinition().Equals( typeof (Nullable <> )))
        {
             if  (value  ==   null )
                 return   null ;

            System.ComponentModel.NullableConverter nullableConverter  =   new  System.ComponentModel.NullableConverter(conversionType);
            conversionType  =  nullableConverter.UnderlyingType;
        }
         return  Convert.ChangeType(value, conversionType);
    }

     private   static   bool  IsNullOrDBNull( object  obj)
    {
         return  ((obj  is  DBNull)  ||   string .IsNullOrEmpty(obj.ToString()))  ?   true  :  false ;
    }