public sealed class RemarkAttribute : Attribute{public string Remark { get; set; }// 构造函数public RemarkAttribute(string remark){this.Remark = remark;}/// <summary>/// 获取枚举备注属性/// </summary>/// <param name="_enum">枚举类参数</param>/// <returns>String</returns>public static string GetEnumRemark(Enum _enum){string result = string.Empty;Type type = _enum.GetType();FieldInfo fd = type.GetField(_enum.ToString());if (fd != null){object[] attrs = fd.GetCustomAttributes(typeof(RemarkAttribute), false);foreach (RemarkAttribute attr in attrs)result = attr.Remark;}return result;}/// <summary>/// 下拉列表绑定枚举属性值/// </summary>/// <param name="ddl">DropDownList</param>/// <param name="_enum">枚举</param>public static void DataBind(DropDownList ddl, Type _enum){List<StructRemark> list = GetStructRemarkList(_enum);foreach (StructRemark item in list){ListItem listItem = new ListItem();listItem = new ListItem(item.FieldText, item.FieldValue.ToString());ddl.Items.Add(listItem);}}/// <summary>/// 下拉列表绑定枚举属性值(有默认项)/// </summary>/// <param name="ddl">DropDownList</param>/// <param name="_enum">枚举</param>public static void DataBind(DropDownList ddl, Type _enum, string firstValue, string firstText){List<StructRemark> list = GetStructRemarkList(_enum);foreach (StructRemark item in list){ListItem listItem = new ListItem();listItem = new ListItem(item.FieldText, item.FieldValue.ToString());ddl.Items.Add(listItem);}ddl.Items.Insert(0, new ListItem(firstText, firstValue));}/// <summary>/// 把枚举转换成DataTable/// </summary>/// <param name="_enum">枚举</param>public static DataTable GetDataTable(Type _enum){DataTable dt = new DataTable();DataColumn dc = null;dc = dt.Columns.Add("Value", Type.GetType("System.Int32"));dc = dt.Columns.Add("Text", Type.GetType("System.String"));DataRow dr = null;List<StructRemark> list = GetStructRemarkList(_enum);foreach (StructRemark item in list){dr = dt.NewRow();dr["Value"] = item.FieldValue;dr["Text"] = item.FieldText;dt.Rows.Add(dr);}return dt;}/// <summary>/// 获取枚举备注属性集/// </summary>/// <param name="_enum">枚举</param>/// <returns>枚举属性结构</returns>public static List<StructRemark> GetStructRemarkList(Type _enum){List<StructRemark> list = new List<StructRemark>();StructRemark model = new StructRemark();foreach (int value in Enum.GetValues(_enum)){model.FieldValue = value;FieldInfo fd = _enum.GetField(Enum.GetName(_enum, value));string name = string.Empty;if (fd == null)name = "";object[] attrs = fd.GetCustomAttributes(typeof(RemarkAttribute), false);foreach (RemarkAttribute attr in attrs){name = attr.Remark;}model.FieldText = name;list.Add(model);}return list;}/// <summary>/// 枚举属性结构/// </summary>public struct StructRemark{public int FieldValue;//值public string FieldText;//键}}
特性 Attribute：
公共语言运行时允许添加类似关键字的描述声明，叫做attributes, 它对程序中的元素进行标注，如类型、字段、方法和属性等。Attributes和Microsoft .NET Framework文件的元数据保存在一起，可以用来向运行时描述你的代码，或者在程序运行的时候影响应用程序的行为。
我们简单的总结为：定制特性attribute，本质上是一个类，其为目标元素提供关联附加信息，并在运行期以反射的方式来获取附加信息。具体的特性实现方法，在接下来的讨论中继续深入。
自定义特性 public sealed class RemarkAttribute : Attribute 以Attribute Remark则表示你的特性
