/*  User: Peter  Date: 2015/8/10  Time: 19:54                            */   using System;using System.Linq;using System.Collections;using System.Collections.Generic;using Autofac.Extras.Attributed;using Autofac.Features.Metadata;using System.ComponentModel.Composition;using System.Reflection;using System.ComponentModel;using Autofac;namespace testAutofac{        class Testdict:Dictionary
     
          {        public Testdict(string name)        {            this["name"] = name;        }    }    [MetadataAttribute]    class LetterFormatterAttribute : Attribute    {        public string Name { get; private set; }        public int Age { get; private set; }             public LetterFormatterAttribute(IDictionary
      
        dict)        {            Name = dict["Name"].ToString();                        Age =int.Parse(dict["Age"].ToString());                    }             public LetterFormatterAttribute(string name,int Age)        {            Name = name;            this.Age = Age;        }         }    interface ILetterFormatter    {        string FormatLetter(string content);    }            [LetterFormatter("Personal2",20)]    class ImpersonalLetterFormatter : ILetterFormatter    {        public ImpersonalLetterFormatter()        {            Console.WriteLine("ImpersonalLetterFormatter");        }        public string FormatLetter(string content)        {            return "To Whom It May Concern:nn" + content;        }    }    [LetterFormatter("Personal",10)]    class PersonalLetterFormatter : ILetterFormatter    {        public PersonalLetterFormatter()        {            Console.WriteLine("PersonalLetterFormatter");        }        public string FormatLetter(string content)        {            return "Dear Individual,nn" + content;        }                    }        interface ITop    {         string   FormatLetter(string name ,string content);    }     class Top:ITop    {        IEnumerable
       
       
        
         , LetterFormatterAttribute>> _letters;        public Top(IEnumerable
         
         
          
           , LetterFormatterAttribute>> letters) { _letters = letters; } public string FormatLetter(string name ,string content) { var letterPersonal = _letters.First( x=> { Console.WriteLine(x.Metadata.Age); return x.Metadata.Name==name ; } ); return letterPersonal.Value.Value.FormatLetter(content); } } class Program { public static void Main(string[] args) { var builder = new ContainerBuilder(); builder.RegisterModule
           
            (); builder.RegisterAssemblyTypes(typeof(Program).Assembly) .AsImplementedInterfaces(); var container = builder.Build(); var top = container.Resolve
            
             (); Console.WriteLine(top.FormatLetter("Personal2","aaa")); Console.ReadKey(true); } }}
            
           
          
         
        
       
      
     

主要测试autofac 的注入

IEnumerable<Meta<Lazy<ILetterFormatter>, LetterFormatterAttribute>>

一个接口实现多类，用Attribute来判断那个可以使用。

  <package id="Autofac" version="3.1.0" targetFramework="net40" />

  <package id="Autofac.Extras.Attributed" version="3.1.0" targetFramework="net40" />

 

Attribute类一定要有一个构造有参数IDictionary<string, object>， autofac通过这个反射入值。