Use. NET proxy mode to do class enhancements

We have implemented the user registration function and now want to increase the logging function. In particular, before and after the user registration, output a log respectively. We can of course modify the original business code.

Now ask two questions from another angle:
1. Team development, we are likely to not get the source code, how to increase this function.
2. This demand is to increase the log, and then add other requirements (such as exception handling), is still to change the business class it.

To sum up:
We want to do the enhancements of the class without modifying the original business code. Our design should conform to the object-oriented principle: open to expansion, closed to modification .

There are ways to do that. We try the following methods: use the adorner pattern to do the enhanced use of the class . NET proxy mode to do class enhancements use Castle to do class enhancements use Unity to do class enhancements (continued) use AUTOFAC to do class enhancements Original Business Class

Business model

Namespace Testaopbydecorator
{public
    class User
    {public
        string Name {get; set;}
        public int Id {get; set;}}}

Interface design

Namespace Testaopbydecorator
{public
    interface iuserprocessor
    {
        void RegisterUser (user user);
    }
}

Business implementation

Using System;

Namespace Testaopbydecorator
{public
    class Userprocessor:iuserprocessor
    {public
        void RegisterUser (User user)
        {
            if (user = null)
            {return
                ;
            }

            Console.WriteLine (String. Format ("registered with a user {0}:{1}", user.) Id, user. Name);}
        }

Upper Call

Using System;

Namespace Testaopbydecorator
{
    class program
    {
        private static user user = new User {Id = 1, Name = "Yunnan Red "};

        static void Main (string[] args)
        {
            Register ();
            Console.readkey ();
        }

        private static void Register ()
        {
            Iuserprocessor processor = new Userprocessor ();
            Processor. RegisterUser (user);}}

use. NET proxy mode to do class enhancements

We will use the System.Runtime.Remoting.Proxies.RealProxy provided by. NET to do business enhancements to the existing classes.

Using System;
Using System.Runtime.Remoting.Messaging;

Using System.Runtime.Remoting.Proxies; Namespace Testaopbyproxy {public class Userprocessorproxy:realproxy {private Iuserprocessor _processor

        ; Public Userprocessorproxy (Iuserprocessor processor): Base (typeof (Iuserprocessor)) {this._processor =
        Processor public override IMessage Invoke (IMessage msg) {IMethodCallMessage Callmessage = (IMETHODCA
            Llmessage) msg;

            User user = Callmessage.args[0] as user;
            Before (user);
            Object returnvalue = (imethodreturnmessage) callMessage.MethodBase.Invoke (This._processor, Callmessage.args);

            After (user);
        return new ReturnMessage (returnvalue, new object[0], 0, NULL, callmessage); } private void after (user) {Console.WriteLine ("Registered Users:") + user.
        Name);
       } private void before (user user) {     Console.WriteLine ("Pre-registered User:") + user.
        Name);

 }
    }
}

Upper Call

Using System;

Namespace Testaopbyproxy
{
    class program
    {
        private static user user = new User {Id = 1, Name = "Dianhong"};
  static void Main (string[] args)
        {
            registerandlog ();
            Console.readkey ();
        }

        private static void Registerandlog ()
        {
            Iuserprocessor processor = new Userprocessor ();
            Iuserprocessor proxy = (iuserprocessor) new Userprocessorproxy (processor). Gettransparentproxy ()//Agent of the original business class
            proxy. RegisterUser (user)//compliance Interface Contract}}

Compare the business presentation before and after the expansion