自定义Attribute

System.ComponentModel名称空间中提供了很多属性标记在不同场合使用，比如可以使用[Descirpiton]属性对类型、方法或枚举等进行描述。如果系统提供的标记不能满足要求，可以自定义属性，下面是示例代码：

using System;

namespace ZL.NameAttribute
{
    [System.AttributeUsage(System.AttributeTargets.All)]
    public class MyNameAttribute : System.Attribute
    {
        private string name;
        private string description;

        public MyNameAttribute(string name,string description)
        {
            this.name = name;
            this.description = description;
        }

        public string Name { get { return name; } }
        public string Description { get { return description; } }   
    }
}

使用System.AttributeUsage来规定标记的使用范围。如果希望提取这些属性，可以使用反射方法：

using System.Reflection;
using ZL.NameAttribute;

namespace ZL.GetNameAttribute
{
    public class Utility
    {
        public static void GetAttribute(Type t)
        {
            MyNameAttribute att;

            // Get the class-level attributes.

            // Put the instance of the attribute on the class level in the att object.
            att = (MyNameAttribute)Attribute.GetCustomAttribute(t, typeof(MyNameAttribute));

            if (att != null)
            {
                Console.WriteLine("The Name Attribute on the class level is: {0}.", att.Name);
                Console.WriteLine("The Description Attribute on the class level is: {0}.", att.Description);
            }

            // Get the method-level attributes.

            // Get all methods in this class, and put them
            // in an array of System.Reflection.MemberInfo objects.
            MemberInfo[] MyMemberInfo = t.GetMethods();

            // Loop through all methods in this class that are in the
            // MyMemberInfo array.
            for (int i = 0; i < MyMemberInfo.Length; i++)
            {
                att = (MyNameAttribute)Attribute.GetCustomAttribute(MyMemberInfo[i], typeof(MyNameAttribute));
                if (att!= null)
               {
                    Console.WriteLine("The Name Attribute for the {0} member is: {1}.",
                        MyMemberInfo[i].ToString(), att.Name);
                    Console.WriteLine("The Description Attribute for the {0} member is: {1}.",
                        MyMemberInfo[i].ToString(), att.Description);
                   
                }
            }
        }
    }
}