反射實踐(assembly reflection attribute)

一直都大概知道個意思，從來沒實踐過，今天花了一點時間實踐了一下。

1. 先從assembly裏找type

2. 判斷type的attribute是否是自己想要的

3. 從type裏找member

4. 判斷member的attribute

5. 實例化type

6. invoke function

要被反射的assembly

namespace ConsoleApplication1
{
    class MyFunction1Attribute : Attribute
    { }

    class MyClass1Attribute : Attribute
    { }

    class MyFunction2Attribute : Attribute
    { }

    class MyClass2Attribute : Attribute
    { }

    [MyClass1]
    class MyClass1
    {
        [MyFunction1]
        public void VoidFunc1()
        {
            Console.WriteLine("MyClass1::VoidFunc1");
        }
        [MyFunction2]
        public void VoidFunction2()
        {
            Console.WriteLine("MyClass1::VoidFunction2");
        }
        public int data;
    }


    [MyClass2]
    class MyClass2
    {
        [MyFunction1]
        public void VoidFunc1()
        {
            Console.WriteLine("MyClass2::VoidFunc1");
        }

        [MyFunction2]
        public void VoidFunc2()
        {
            Console.WriteLine("MyClass2::VoidFunc2");
        }
        public int data;
    }
}

找想要的attribute，再invoke

namespace ConsoleApplication1
{
    class Program
    {
        public static void Main(string[] args)
        {
            int _class = 2;
            int _func = 1;

            string expectedClass = "consoleapplication1.myclass"+_class+"attribute";

            string expectedFunciton = "consoleapplication1.myfunction"+_func+"attribute";

            try
            {
                Assembly a = Assembly.LoadFile(@"..\MyClasses.dll");
                foreach (Type t in a.GetTypes())
                {
                    foreach (object oMyClass1Attribute in t.GetCustomAttributes(false))
                    {
                        Attribute myClass1Attribute = oMyClass1Attribute as Attribute;
                        if (myClass1Attribute.ToString().Equals(expectedClass, StringComparison.InvariantCultureIgnoreCase))
                        {
                            foreach (MethodInfo mi in t.GetMethods())
                            {
                                foreach(object oMyFunciton1Attribute in mi.GetCustomAttributes(false))
                                {
                                    Attribute myFunction1Attibute = oMyFunciton1Attribute as Attribute;
                                    if (myFunction1Attibute.ToString().Equals(expectedFunciton , StringComparison.InvariantCultureIgnoreCase))
                                    {
                                        ConstructorInfo ci = t.GetConstructor(new Type[] { });
                                        object myClass1Instance = ci.Invoke(new object[] { });
                                        mi.Invoke(myClass1Instance, new object[] { });
                                    }
                                }
                            }
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
        }
    }    
}