C# 反射之SqlDatareader转换为Model实体.

虽说反射的效率比较低,但是在当今的时代,盛行的大数据,以及高并发的产生,硬件的产能正在逐渐的提升,所以我们可以用空间来换取时间.反射所消耗的那些性能问题其实在企业级开发而言也就无所谓了.二 : 反射得确是可以提升开发效率.

将SqlDataReader反射转换为Model实体,省去了每个Reader还要判断转换一下,如此消耗开发效率的问题,怎么能容忍呢?

代码 :

         /// <summary>
         ///   将SqlDataReader转换为Model实体
         /// </summary>
         /// <typeparam name="T">实例类名</typeparam>
         /// <param name="dr">Reader对象</param>
         /// <returns>实体对象</returns>
         public static T ReaderToModel<T>(IDataReader dr)
         {
             try
             {
                 using (dr)
                 {
                     if (dr.Read())
                     {
                         Type modelType = typeof(T);
                         T model = Activator.CreateInstance<T>();
                         for (int i = ; i < dr.FieldCount; i++)
                         {
                             if(!IsNullOrDbNull(dr[i]))
                             {
                                 PropertyInfo pi = modelType.GetProperty(GetPropertyName(dr.GetName(i)));
                                 pi.SetValue(model, HackType(dr[i], pi.PropertyType), null);
                             }
                         }
                         return model;
                     }
                 }
                 return default(T);
             }
             catch (Exception)
             {

                 throw;
             }
         } 

         /// <summary>
         ///  对可空类型进行判断.
         /// </summary>
         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);
         }

         /// <summary>
         ///  判断字段值是否为NUll
         /// </summary>
         /// <param name="obj"></param>
         /// <returns></returns>
         private static bool IsNullOrDbNull(object obj)
         {
             return ((obj is DBNull) || string.IsNullOrEmpty(obj.ToString())) ? true : false;
         }

         /// <summary>
         ///  获取属性类的名称
         /// </summary>
         /// <param name="column">列名</param>
         /// <returns>列名</returns>
         private static string GetPropertyName(string column)
         {
             string[] narr = column.Split('_');
             column = "";
             for (int i = ; i < narr.Length; i++)
             {
                 if (narr[i].Length > )
                 {
                     column += narr[i].Substring(, ).ToUpper() + narr[i].Substring();
                 }
                 else
                 {
                     column += narr[i].Substring(, ).ToUpper();
                 }
             }
             return column;
         }