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;
    }