c# MEF框架（三导出类的方法和属性）

转自：http://www.cnblogs.com/yunfeifei/p/3927663.html

前面说完了导入和导出的几种方法，如果大家细心的话会注意到前面我们导出的都是类，那么方法和属性能不能导出呢？？？答案是肯定的，下面就来说下MEF是如何导出方法和属性的。

　　还是前面的代码，第二篇中已经提供了下载链接，大家可以下载学习。

　　首先来说导出属性，因为这个比较简单，和导出类差不多，先来看看代码，主要看我加注释的地方，MusicBook.cs中的代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel.Composition;namespace MEFDemo
{[Export("MusicBook")]public class MusicBook : IBookService{//导出私有属性[Export(typeof(string))]private string _privateBookName = "Private Music BookName";//导出公有属性[Export(typeof(string))]public string _publicBookName = "Public Music BookName";public string BookName { get; set; }}[Export("MathBook", typeof(IBookService))]public class MathBook : IBookService{public string BookName { get; set; }public string GetBookName(){return "MathBook";}}[Export("HistoryBook", typeof(IBookService))]public class HistoryBook : IBookService{public string BookName { get; set; }public string GetBookName(){return "HistoryBook";}}}

program.cs中的代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.ComponentModel.Composition;
using System.ComponentModel.Composition.Hosting;namespace MEFDemo
{class Program{[ImportMany("MathBook")]public IEnumerable<object> Services { get; set; }//导入属性，这里不区分public还是private
      [ImportMany]public List<string> InputString { get; set; }static void Main(string[] args){Program pro = new Program();pro.Compose();if (pro.Services != null){foreach (var s in pro.Services){var ss = (IBookService)s;Console.WriteLine(ss.GetBookName());}}foreach (var str in pro.InputString){Console.WriteLine(str);}Console.Read();}private void Compose(){var catalog = new AssemblyCatalog(Assembly.GetExecutingAssembly());CompositionContainer container = new CompositionContainer(catalog);container.ComposeParts(this);}}
}

下面还用foreach遍历输出属性的值，运行即可查看到结果。最后我会附上源码供大家下载，这里就不再截图了。

下面说导出方法吧，同理无论是公有方法还是私有方法都是可以导出的，MusicBook代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel.Composition;namespace MEFDemo
{[Export("MusicBook")]public class MusicBook : IBookService{//导出私有属性[Export(typeof(string))]private string _privateBookName = "Private Music BookName";//导出公有属性[Export(typeof(string))]public string _publicBookName = "Public Music BookName";public string BookName { get; set; }//导出公有方法[Export(typeof(Func<string>))]public string GetBookName(){return "MusicBook";}//导出私有方法[Export(typeof(Func<int, string>))]private string GetBookPrice(int price){return "$" + price;}}[Export("MathBook", typeof(IBookService))]public class MathBook : IBookService{public string BookName { get; set; }public string GetBookName(){return "MathBook";}}[Export("HistoryBook", typeof(IBookService))]public class HistoryBook : IBookService{public string BookName { get; set; }public string GetBookName(){return "HistoryBook";}}}

program中的代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.ComponentModel.Composition;
using System.ComponentModel.Composition.Hosting;namespace MEFDemo
{class Program{[ImportMany("MathBook")]public IEnumerable<object> Services { get; set; }//导入属性，这里不区分public还是private
      [ImportMany]public List<string> InputString { get; set; }//导入无参数方法
      [Import]public Func<string> methodWithoutPara { get; set; }//导入有参数方法
      [Import]public Func<int,string> methodWithPara { get; set; }static void Main(string[] args){Program pro = new Program();pro.Compose();if (pro.Services != null){foreach (var s in pro.Services){var ss = (IBookService)s;Console.WriteLine(ss.GetBookName());}}foreach (var str in pro.InputString){Console.WriteLine(str);}//调用无参数方法if (pro.methodWithoutPara != null){Console.WriteLine(pro.methodWithoutPara());}//调用有参数方法if (pro.methodWithPara != null){Console.WriteLine(pro.methodWithPara(3000));}Console.Read();}private void Compose(){var catalog = new AssemblyCatalog(Assembly.GetExecutingAssembly());CompositionContainer container = new CompositionContainer(catalog);container.ComposeParts(this);}}
}