关于代理类的使用情景和基本代码

当你做好一个项目的时候,你突然发现运行起来比较慢,各种异常又没有写进日志里面,这种想做一些监测,比如看某个类每个方法执行时间,把异常进行管理,但没有人愿意把每个方法都写上监测逻辑,那这时代理就有了使用场景,主要是只要修改不多的程序,就可以让某类在方法或属性被调用时,先访问某个方法.具体如下:

代码:

被代理的类

public class Class2 : MarshalByRefObject
    {
        private  Class2()
        { 
        }
        public static Class2 CreateInstance()
        {
            Class2 mobj = new Class2();
            proxytem realProxy = new proxytem(typeof(Class2),mobj);
            Class2 refObj = (Class2)realProxy.GetTransparentProxy();
            return refObj;
        }
        public int sum()
        {
            return 9;
        }
    }

proxytem 类

public class proxytem : RealProxy
    {
        MarshalByRefObject myMarshalByRefObject;

        public proxytem(Type myType, MarshalByRefObject mobj)
            : base(myType)
        {
            myMarshalByRefObject = mobj;
        }
        public override System.Runtime.Remoting.Messaging.IMessage Invoke(System.Runtime.Remoting.Messaging.IMessage message)
        {
            System.Runtime.Remoting.Messaging.IMessage retMsg = null;
            if (message is IConstructionCallMessage)
            {
                IConstructionCallMessage ccm = (IConstructionCallMessage)message;
                RemotingServices.GetRealProxy(myMarshalByRefObject).InitializeServerObject(ccm);
                ObjRef objRef = RemotingServices.Marshal(myMarshalByRefObject);
                RemotingServices.Unmarshal(objRef);
                retMsg = EnterpriseServicesHelper.CreateConstructionReturnMessage(ccm, (MarshalByRefObject)this.GetTransparentProxy());
            }
            else if (message is IMethodCallMessage)
            {
                IMethodCallMessage mcm = (IMethodCallMessage)message;
                DateTime start = DateTime.Now;
                //执行方法调用
                retMsg = RemotingServices.ExecuteMessage(myMarshalByRefObject, mcm);
                IMethodReturnMessage mrm = (IMethodReturnMessage)retMsg;
                DateTime end = DateTime.Now;
                //有了start和end就可以统计时间
                Exception ex = mrm.Exception;
                //如果没有异常，就进行序列化测试,SerializeHelper这个类可以检测对象是否可序列化,具体百度一下
                //if (ex == null)
                //{
                //    try
                //    {
                //        SerializeHelper.DataContractSerializer(mrm.ReturnValue);
                //    }
                //    catch (Exception e)
                //    {
                //        ex = e;
                //    }
                //}
                ObjRef objRef = RemotingServices.Marshal(myMarshalByRefObject);//获得原来的类的实例
                MethodInfo mi = mcm.MethodBase.DeclaringType.GetMethod(mcm.MethodName);//获得方法信息
                Activator.CreateInstance(mi.ReturnType);//可以获得方法反回类型的实例,这就保证方法不会报错,一定会返回一个new出来的实例
               object a= ((ReturnMessage)retMsg).ReturnValue;//可以得到返回值.
            }
          
            return retMsg;
        }
    }

调用:

Class2 c2 = Class2.CreateInstance();
            int i =c2.sum();

1.被代理的类要继承MarshalByRefObject类,RealProxy是系统的一个基本代理类,new RealProxy(MarshalByRefObject)后,如果访问MarshalByRefObject实例的方法,就会调用RealProxy.Invoke的方法,利用这一点,找个类继承RealProxy,把实例也传进去,然后重写invoke,在invoke里面利用 retMsg = RemotingServices.ExecuteMessage(myMarshalByRefObject, mcm);
来执行方法,同时也可以做很多统计工作