反射

using System;
using System.Reflection;

// 反射 (Reflection)
// 可以通过类，属性，方法的名字来使用类，属性，方法
namespace A {
    class Person {
        public int age;
        private int score;
        private readonly int money = 1000;
        private static int ac;

        public Person() {
            Console.WriteLine("Person的构造方法被调用");
        }

        public Person(int a, int b) {
            Console.WriteLine("Person的有参构造被调用");
        }

        public override string ToString() {
            return "age = " + age + "; score = " + score + "; money = " + money;
        }


        public void Show(int a) {
            Console.WriteLine("Show -> " + a);
        }

        private static int Display(int a) {
            return a * a;
        }

        private void Add(int a) {
            Console.WriteLine("Add(int)");
        }
        private void Add(int a, string b) {
            Console.WriteLine("Add(int, string)");
        }
    }


    class Test {
        public static void Main(string[] args) {
            // 实例化一个Person对象

            // 1、获取这个类的类型
            Type t = Type.GetType("A.Person");
            Console.WriteLine(t);

            // 2、通过反射实例化一个类的对象
            // 通过无参的构造方法来实例化对象
            object obj = Activator.CreateInstance(t);
            // 通过有参的构造方法来实例化对象
            object obj1 = Activator.CreateInstance(t, new object[] { 1, 2 });

            // 3、通过属性名来访问属性(public, instance)
            FieldInfo f = t.GetField("age");
            // xiaoming.age = 10;
            f.SetValue(obj, 20);
            Console.WriteLine(obj);
            Console.WriteLine(f.GetValue(obj));

            // 4、访问属性，非公开的
            // BindingFlags默认值: BindingFlags.Public | BindingFlags.Instance
            FieldInfo ff = t.GetField("score", BindingFlags.NonPublic | BindingFlags.Instance);
            ff.SetValue(obj, 100);
            Console.WriteLine(obj);

            // 5、访问属性，readonly
            FieldInfo fff = t.GetField("money", BindingFlags.NonPublic | BindingFlags.Instance);
            fff.SetValue(obj, 9999);
            Console.WriteLine(obj);

            // 6、访问属性，静态的
            FieldInfo ac = t.GetField("ac", BindingFlags.NonPublic | BindingFlags.Static);
            ac.SetValue(null, 10000);
            Console.WriteLine(ac.GetValue(null));

            // 7、访问方法(public 没有重载的方法)
            MethodInfo m0 = t.GetMethod("Show");
            m0.Invoke(obj, new object[] { 1 });

            // 8、访问方法(Nonpublic, static)
            MethodInfo m1 = t.GetMethod("Display", BindingFlags.NonPublic | BindingFlags.Static);
            object result = m1.Invoke(null, new object[] { 10 });
            Console.WriteLine(result);

            // 9、访问有重载的方法
            MethodInfo m2 = t.GetMethod("Add", BindingFlags.NonPublic|BindingFlags.Instance, null, new Type[] { typeof(int), typeof(string) }, null);
            m2.Invoke(obj, new object[] { 1, "hello" });
        }
    }
}