DataReader转实体类代码,CSharp代码库,德仔网

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【CSharp】 DataReader转实体类
作者:合营 / 发布于2015/4/20/ 867

	/// <summary>
	 /// DataReader转泛型
	 /// </summary>
	 /// <typeparam name="T">传入的实体类</typeparam>
	 /// <param name="objReader">DataReader对象</param>
	 /// <returns></returns>
	 public static IList<T> ReaderToList<T>(this IDataReader objReader)
	 {
	 using (objReader)
	 {
	 List<T> list = new List<T>();

	 //获取传入的数据类型
	 Type modelType = typeof(T);

	 //遍历DataReader对象
	 while (objReader.Read())
	 {
	 //使用与指定参数匹配最高的构造函数，来创建指定类型的实例
	 T model = Activator.CreateInstance<T>();
	 for (int i = 0; i < objReader.FieldCount; i++)
	 {
	 //判断字段值是否为空或不存在的值
	 if (!IsNullOrDBNull(objReader[i]))
	 {
	 //匹配字段名
	 PropertyInfo pi = modelType.GetProperty(objReader.GetName(i), BindingFlags.GetProperty | BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase);
	 if (pi != null)
	 {
	 //绑定实体对象中同名的字段
	 pi.SetValue(model, CheckType(objReader[i], pi.PropertyType), null);
	 }
	 }
	 }
	 list.Add(model);
	 }
	 return list;
	 }
	 }

	 /// <summary>
	 /// 对可空类型进行判断转换(*要不然会报错)
	 /// </summary>
	 /// <param name="value">DataReader字段的值</param>
	 /// <param name="conversionType">该字段的类型</param>
	 /// <returns></returns>
	 private static object CheckType(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>
	 /// 判断指定对象是否是有效值
	 /// </summary>
	 /// <param name="obj"></param>
	 /// <returns></returns>
	 private static bool IsNullOrDBNull(object obj)
	 {
	 return (obj == null || (obj is DBNull)) ? true : false;
	 }

	
	/// <summary>
	 /// DataReader转模型
	 /// </summary>
	 /// <typeparam name="T"></typeparam>
	 /// <param name="objReader"></param>
	 /// <returns></returns>
	 public static T ReaderToModel<T>(this IDataReader objReader)
	 {

	 using (objReader)
	 {
	 if (objReader.Read())
	 {
	 Type modelType = typeof(T);
	 int count = objReader.FieldCount;
	 T model = Activator.CreateInstance<T>();
	 for (int i = 0; i < count; i++)
	 {
	 if (!IsNullOrDBNull(objReader[i]))
	 {
	 PropertyInfo pi = modelType.GetProperty(objReader.GetName(i), BindingFlags.GetProperty | BindingFlags.Public | BindingFlags.Instance | BindingFlags.IgnoreCase);
	 if (pi != null)
	 {
	 pi.SetValue(model, CheckType(objReader[i], pi.PropertyType), null);
	 }
	 }
	 }
	 return model;
	 }
	 }
	 return default(T);
	 }
试试其它关键字
　实体类　　 DataReader　
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