关于Attribute的一些学习

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namespace Con_Attribute
{
    /// <summary>
    ///  "Sports" 是给构造函数的赋值， Level = 5 是给属性的赋值。
    /// </summary>
    [HobbyAttribute("Sports", Level = 5)]
    class Student
    {
        public string profession;
        public string Profession
        {
            get { return profession; }
            set { profession = value; }
        }
    }

    class HobbyAttribute : System.Attribute
    {
        //兴趣类型
        private string type;
        public string Type
        {
            get { return type; }
            set { type = value; }
        }

        //兴趣指数
        private int level;
        public int Level
        {
            get { return level; }
            set { level = value; }
        }

        /// <summary>
        /// 构造函数
        /// </summary>
        /// <remarks>参数值为null的string 危险，所以必需在构造函数中赋值</remarks>
        /// <param name="_type"></param>
        public HobbyAttribute(string _type)
        {
            this.Type = _type;
        }
    }
}

下面我们来调用一下看看效果：

class Program
    {
        static void Main(string[] args)
        {
            #region demo2

            //通过反射得到Student类的信息
            System.Reflection.MemberInfo info = typeof(Student);
            HobbyAttribute hobbyatt = (HobbyAttribute)Attribute.GetCustomAttribute(info, typeof(HobbyAttribute));
            if (hobbyatt != null)
            {
                Console.WriteLine("类名：{0}", info.Name);
                Console.WriteLine("兴趣类型：{0}", hobbyatt.Type);
                Console.WriteLine("兴趣指数：{0}", hobbyatt.Level.ToString());
                Console.Read();
            }
            #endregion
        }
    }

运行结果如下：



或许我们能做些事情，比如页面权限控制。通过Attribute得到该页面.cs类的信息，然后去数据库里面的权限部分匹配，嗯，只是一个思路吧，回头再看看其它效果。

//属性测试
	//[TestAttribute(ccvalue="hello")]
	public class AATest : UIButton
	{
		public AATest ()
		{
		}
	}

	//[AttributeUsage(AttributeTargets.Method|AttributeTargets.Class)] 
	[AttributeUsage(AttributeTargets.Method, AllowMultiple = false)] //TestAttribute类仅作用在方法上
	public class TestAttribute : Attribute
	{
		public string Role{ get; set;}
		public TestAttribute(string role)
		{
			this.Role = role;
		}

		public TestAttribute()
		{

		}
	}

	public class SysDataManager
	{
		public SysDataManager()
		{

		}

		[TestAttribute("anyone")]
		public void ShowInfo()
		{
			Utils.Tools.Alert ("anyone:ShowInfo()");
		}

		[TestAttribute("admin")]
		public void Out2Excel()
		{
			Utils.Tools.Alert ("admin:Out2Excel()");
		}

		public void DeleteInfo()
		{
			Utils.Tools.Alert ("DeleteInfo()");
		}
	}

	public static class OperationInvoker
	{
		public static void Invoke(object target, string role, string operationName, object[] param)
		{
			var methordinfo = target.GetType ().GetMethod (operationName); //获取所有方法

			if (methordinfo.IsDefined (typeof(TestAttribute), false)) {
				var permissons = methordinfo.GetCustomAttributes (typeof(TestAttribute), false).OfType<TestAttribute> ();
				if (permissons.Any (x => x.Role == role)) {
					methordinfo.Invoke (target, param);
				} else {
					//Console.WriteLine (string.Format ("{0}", role, operationName));
					Utils.Tools.Alert (string.Format ("角色{0}没有访问操作{1}的权限！", role, operationName));
					//throw new Exception (string.Format ("角色{0}没有访问操作{1}的权限！", role, operationName));
				}
			}
		}

		//...

	}