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動態(tài)代理的5模式使用示例和Mixin模式

更新時間：2013年11月25日 10:18:37 作者：

什么叫"動態(tài)代理"，代理模式我們都知道，動態(tài)代理就是動態(tài)生成的代理（采用Emit）。5種代理模式:ClassProxy、ClassProxyWithTarget、InterfaceProxyWithoutTarget、InterfaceProxyWithTarget、InterfaceProxyWithTargetInterface、Mixin模式

重量級的ORM和IOC產(chǎn)品離不開動態(tài)代理，作為開發(fā)人員，多數(shù)情況不用關(guān)注動態(tài)代理的內(nèi)部實現(xiàn)機制，但是了解其一般的規(guī)律和模式還是有必要的，比如：雖然你開發(fā)期間采用了POCO，因為開啟了動態(tài)代理，運行期間則不是POCO。本文簡單描述了5種代理生成模式和1種Mixin模式，最后給出一個示例。

復(fù)制代碼代碼如下:

public interface IPlayable
    {
        void Play();
    }

    public class Animal : IPlayable
    {
        public virtual void Play()
        {
            Console.WriteLine("Animal.Play");
        }
    }

    public class Dog : Animal
    {
        public override void Play()
        {
            Console.WriteLine("Dog.Play");
        }
    }

    public interface IRunable
    {
        void Run();
    }

    public class RunAbility : IRunable
    {
        public void Run()
        {
            Console.WriteLine("RunAbility.Run");
        }
    }

    public class AnimalInterceptor : IInterceptor
    {
        public void Intercept(IInvocation invocation)
        {
            Console.WriteLine("Before AnimalInterceptor.Intercept");
            if (invocation.InvocationTarget != null)
            {
                invocation.Proceed();
            }
            Console.WriteLine("After AnimalInterceptor.Intercept");
        }
    }

第一種：ClassProxy

復(fù)制代碼代碼如下:

{
                Console.WriteLine("\n*************ClassProxy*************\n");
                var generator = new ProxyGenerator();
                var animal = generator.CreateClassProxy<Animal>(new AnimalInterceptor());
                animal.Play();

Console.WriteLine(animal.GetType());
Console.WriteLine(animal.GetType().BaseType);

var compositeField = animal.GetType().GetField("__target");
Console.WriteLine(compositeField);

                foreach (var interfaceType in animal.GetType().GetInterfaces())
                {
                    Console.WriteLine(interfaceType);
                }
            }

第二種：ClassProxyWithTarget

復(fù)制代碼代碼如下:

{
                Console.WriteLine("\n*************ClassProxyWithTarget*************\n");
                var generator = new ProxyGenerator();
                var animal = generator.CreateClassProxyWithTarget<Animal>(new Dog(), new AnimalInterceptor());
                animal.Play();

Console.WriteLine(animal.GetType());
Console.WriteLine(animal.GetType().BaseType);

var compositeField = animal.GetType().GetField("__target");
Console.WriteLine(compositeField);

                foreach (var interfaceType in animal.GetType().GetInterfaces())
                {
                    Console.WriteLine(interfaceType);
                }
            }

第三種：InterfaceProxyWithoutTarget

復(fù)制代碼代碼如下:

{
                Console.WriteLine("\n*************InterfaceProxyWithoutTarget*************\n");
                var generator = new ProxyGenerator();
                var animal = generator.CreateInterfaceProxyWithoutTarget<IPlayable>(new AnimalInterceptor());
                animal.Play();

Console.WriteLine(animal.GetType());
Console.WriteLine(animal.GetType().BaseType);

var compositeField = animal.GetType().GetField("__target");
Console.WriteLine(compositeField);

                foreach (var interfaceType in animal.GetType().GetInterfaces())
                {
                    Console.WriteLine(interfaceType);
                }
            }

第四種：InterfaceProxyWithTarget

復(fù)制代碼代碼如下:

{
                Console.WriteLine("\n*************InterfaceProxyWithTarget*************\n");
                var generator = new ProxyGenerator();
                var animal = generator.CreateInterfaceProxyWithTarget<IPlayable>(new Dog(), new AnimalInterceptor());
                animal.Play();

Console.WriteLine(animal.GetType());
Console.WriteLine(animal.GetType().BaseType);

var compositeField = animal.GetType().GetField("__target");
Console.WriteLine(compositeField);

                foreach (var interfaceType in animal.GetType().GetInterfaces())
                {
                    Console.WriteLine(interfaceType);
                }
            }

第五種：InterfaceProxyWithTargetInterface

復(fù)制代碼代碼如下:

{
                Console.WriteLine("\n*************InterfaceProxyWithTargetInterface*************\n");
                var generator = new ProxyGenerator();
                var animal = generator.CreateInterfaceProxyWithTargetInterface<IPlayable>(new Dog(), new AnimalInterceptor());
                animal.Play();

Console.WriteLine(animal.GetType());
Console.WriteLine(animal.GetType().BaseType);

var compositeField = animal.GetType().GetField("__target");
Console.WriteLine(compositeField);

                foreach (var interfaceType in animal.GetType().GetInterfaces())
                {
                    Console.WriteLine(interfaceType);
                }
            }

Mixin模式

復(fù)制代碼代碼如下:

{
                Console.WriteLine("\n*************Mixin*************\n");
                var generator = new ProxyGenerator();
                var options = new ProxyGenerationOptions();
                options.AddMixinInstance(new RunAbility());
                var animal = generator.CreateClassProxy<Animal>(options, new AnimalInterceptor());
                animal.Play();
                (animal as IRunable).Run();

Console.WriteLine(animal.GetType());
Console.WriteLine(animal.GetType().BaseType);

var compositeField = animal.GetType().GetField("__target");
Console.WriteLine(compositeField);

                foreach (var field in animal.GetType().GetFields())
                {
                    if (field.Name.StartsWith("__mixin"))
                    {
                        Console.WriteLine(field);
                    }
                }

                foreach (var interfaceType in animal.GetType().GetInterfaces())
                {
                    Console.WriteLine(interfaceType);
                }
            }