C# 反射（Reflection）

using System;
using System.Reflection;
namespace ConsoleTest
{
    // 一个自定义特性 BugFix 被赋给类及其成员
    [AttributeUsage(AttributeTargets.Class |
    AttributeTargets.Constructor |
    AttributeTargets.Field |
    AttributeTargets.Method |
    AttributeTargets.Property,
    AllowMultiple = true)]

    public class DeBugInfo : System.Attribute
    {
        private int bugNo;
        public string message;

        public DeBugInfo(int bg)
        {
            this.bugNo = bg;
        }

        public int BugNo
        {
            get
            {
                return bugNo;
            }
        }
        public string Message
        {
            get
            {
                return message;
            }
            set
            {
                message = value;
            }
        }
    }
    /// 

    /// 矩形
    /// 
    [DeBugInfo(45, Message = "Return type mismatch")]
    [DeBugInfo(49, Message = "Unused variable")]
    public class Rectangle
    {
        public int hight = 0;
        public double length { get; set; }
        public double width { get; set; }
        public Rectangle()
        {
        }
        public Rectangle(double l, double w)
        {
            length = l;
            width = w;
        }
        // 计算面积
        [DeBugInfo(55, Message = "Return type mismatch")]
        public void GetArea()
        {
            Console.WriteLine("面积: {0}", length * width);
        }
        //计算体积
        [DeBugInfo(56)]
        public void GetVolume()
        {
            Console.WriteLine("体积: {0}", length * width * hight);
        }
    }

    class ExecuteRectangle
    {
        public static void Main12()
        {
            //使用对象GetType()方法
            //Rectangle nc = new Rectangle();
            //Type type = nc.GetType();
            
            //使用 C# typeof 运算符
            Type type = typeof(Rectangle);

            // 获取 Rectangle 类的所有成员
            Console.WriteLine("\n遍历 Rectangle 类的成员开始---------------");
            MemberInfo[] minfos = type.GetMembers();
            foreach (var i in minfos)
            {
                Console.WriteLine("成员: {0}", i.Name);
            }
            Console.WriteLine("-------------------结束-------------------");

            // 获取 Rectangle 类的所有构造函数
            Console.WriteLine("\n遍历 Rectangle 类的构造函数开始-----------");
            ConstructorInfo[] ci = type.GetConstructors();
            foreach (var i in ci)
            {
                Console.WriteLine("构造函数: {0}", i.Name);
            }
            Console.WriteLine("-------------------结束-------------------");

            // 获取 Rectangle 类的所有属性
            Console.WriteLine("\n遍历 Rectangle 类的属性开始---------------");
            PropertyInfo[] pis = type.GetProperties();
            foreach (var i in pis)
            {
                Console.WriteLine("属性: {0}", i.Name);
            }
            Console.WriteLine("-------------------结束-------------------");

            // 获取 Rectangle 类的所有public字段
            Console.WriteLine("\n遍历 Rectangle 类的字段开始---------------");
            FieldInfo[] fis = type.GetFields();
            foreach (var i in fis)
            {
                Console.WriteLine("字段: {0}", i.Name);
            }
            Console.WriteLine("-------------------结束-------------------");

            //用反射生成对象，并调用属性、方法和字段进行操作
            Console.WriteLine("\n用反射生成对象，并调用属性、方法和字段进行操作");
            object obj = Activator.CreateInstance(type);// 创建实例
            FieldInfo fi = type.GetField("hight");// 取得length字段 
            fi.SetValue(obj, 5);// 给ID字段赋值 
            PropertyInfo pi1 = type.GetProperty("length");// 取得length属性 
            pi1.SetValue(obj, 10, null);// 给length属性赋值
            PropertyInfo pi2 = type.GetProperty("width");// 取得width属性 
            pi2.SetValue(obj, 20, null);// 给width属性赋值 
            MethodInfo mi = type.GetMethod("GetVolume");// 取得show方法 
            mi.Invoke(obj, null);// 调用GetArea方法
            Console.WriteLine("-------------------结束-------------------");

            // 遍历 Rectangle 类的特性
            Console.WriteLine("\n遍历 Rectangle 类的特性开始---------------");
            Object[] attributes = type.GetCustomAttributes(false);
            foreach (var i in attributes)
            {
                DeBugInfo dbi = i as DeBugInfo;
                if (null != dbi)
                {
                    Console.WriteLine("Bug no: {0}, Message: {1}", dbi.BugNo, dbi.Message);
                }
            }
            Console.WriteLine("-------------------结束-------------------");

            // 遍历 Rectangle 类的方法上的特性(此处只遍历)
            Console.WriteLine("\n遍历 Rectangle 类的方法上的特性开始-------");
            MethodInfo[] m = type.GetMethods(BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Public | BindingFlags.DeclaredOnly);
            foreach (var i in m )
            {
                foreach (Attribute a in i.GetCustomAttributes(true))
                {
                    DeBugInfo dbi = a as DeBugInfo;
                    if (null != dbi)
                    {
                        Console.WriteLine("Bug no: {0}, for Method: {1}, Message: {2}", dbi.BugNo, i.Name, dbi.Message);
                    }
                }
            }
            Console.WriteLine("-------------------结束-------------------");

            Console.ReadLine();
        }
    }
}