.Net AOP (四）EnterpriseLibary 實現方法

.Net AOP (四）EnterpriseLibary 實現方法

首先添加EnterpriseLibary的引用

自定義CallHandler，這裏定義兩個CallHandler分別用於參數檢查和日誌記錄。

using Microsoft.Practices.Unity.InterceptionExtension;

 public class UserHandler:ICallHandler
    {
        public int Order { get; set; }
        public IMethodReturn Invoke(IMethodInvocation input, GetNextHandlerDelegate getNext)
        {
            User user = input.Inputs[0] as User;
            if (user.PassWord.Length < 10)
            {
                return input.CreateExceptionMethodReturn(new UserException("密碼長度不能小於10位"));
            }
            Console.WriteLine("參數檢測無誤");
            return getNext()(input, getNext);
        }
    }

    public class LogHandler:ICallHandler
    {
        public int Order { get; set; }
        public IMethodReturn Invoke(IMethodInvocation input, GetNextHandlerDelegate getNext)
        {
            User user = input.Inputs[0] as User;
            Log log = new Log() { Message = string.Format("RegUser:Username:{0},Password:{1}", user.Name, user.PassWord), Ctime = DateTime.Now };
            Console.WriteLine("日誌已記錄，Message:{0},Ctime:{1}",log.Message,log.Ctime);
            var messagereturn  = getNext()(input, getNext); 
            return messagereturn;
        }
    }

定義對應的HandlerAttribute

using Microsoft.Practices.Unity.InterceptionExtension;
using Microsoft.Practices.Unity;

    public class UserHandlerAttribute : HandlerAttribute
    {
        public override ICallHandler CreateHandler(IUnityContainer container)
        {
            ICallHandler handler = new UserHandler(){Order=this.Order};
            return handler;
        }
    }

    public  class LogHandlerAttribute:HandlerAttribute
    {
        public int Order { get; set; }
        public override ICallHandler CreateHandler(IUnityContainer container)
        {
            return new LogHandler() { Order = this.Order };
        }
    }

用戶註冊接口和實現，這裏通過爲接口添加attribute的方式實現。order值表示執行順序，值小的先執行。

[LogHandlerAttribute(Order=2)]
    [UserHandlerAttribute(Order=1)]
    public interface IUserProcessor
    {
         void RegUser(User user);
    }

    public class UserProcessor : MarshalByRefObject,IUserProcessor
    {
        public  void RegUser(User user)
        {
            Console.WriteLine("用戶已註冊。");
        }
    }

測試

using Microsoft.Practices.EnterpriseLibrary.PolicyInjection; 
   
    public class Client
    {
        public static void Run()
        {
            try
            {
                User user = new User() { Name = "lee", PassWord = "123123123123" };
                UserProcessor userprocessor = PolicyInjection.Create<UserProcessor>();
                userprocessor.RegUser(user);
            }
            catch(Exception ex)
            {
                throw ex;
            }
        }
    }