csharp MEF基础知识

Posted 2021-05-12

using System.ComponentModel.Composition;

using System;
using System.ComponentModel.Composition;
using System.ComponentModel.Composition.Hosting;

namespace MefProject
{
    class Program
    {
        [Export] private string OriginalMessage = "My Message";
        [Import] private string Message;
        
        static void Main(string[] args)
        {
            var p = new Program();
            p.Compose();
        }

        private void Compose()
        {
            var catalog = new AssemblyCatalog(typeof(Program).Assembly);
            var container = new CompositionContainer(catalog);
            container.ComposeParts(this);
            
            // Export: OriginalMessage >> Import: Message
            Console.WriteLine(Message);
        }
    }
}

using System;
using System.ComponentModel.Composition;
using System.ComponentModel.Composition.Hosting;

namespace SeparatingExports
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Composing MEF from another class");
            var loader = new Loader();
            loader.GetCount();
        }
    }

    public class Loader
    {
        [Import] public MefExport MefExportClass;
        public Loader()
        {
            var catalog = new AssemblyCatalog(typeof(MefExport).Assembly);
            var container = new CompositionContainer(catalog);
            container.ComposeParts(this);
        }

        public void GetCount()
        {
            Console.WriteLine(MefExportClass.MyCount);
            Console.WriteLine(MefExportClass.UpdateCount());
        }
    }

    [Export]
    public class MefExport
    {
        public int MyCount { get; set; }

        public MefExport()
        {
            MyCount = 2;
        }

        public int UpdateCount()
        {
            MyCount++;
            return MyCount;
        }
    }
}