Initial checkin

VSMefSample/Apple.cs

@@ -0,0 +1,13 @@
+using System.Composition;
+
+namespace VSMefSample
+{
+    [Export(typeof(Fruit))]
+    [ExportMetadata("Type", "Apple")]
+    public class Apple : Fruit
+    {
+        public bool IsJuicy { get; set; }
+
+        public override string ToString() => $"Apple (IsJuicy: {this.IsJuicy})";
+    }
+}

VSMefSample/Fruit.cs

@@ -0,0 +1,12 @@
+using System.Composition;
+
+namespace VSMefSample
+{
+    public class Fruit
+    {
+        [Import]
+        public Tree GrewFrom { get; set; }
+
+        public int SeedCount { get; set; }
+    }
+}

VSMefSample/FruitMetadata.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace VSMefSample
+{
+    public class FruitMetadata
+    {
+        public FruitMetadata(IDictionary<string, object> metadata)
+        {
+            this.Type = (string)metadata["Type"];
+        }
+
+        public string Type { get; set; }
+    }
+}

VSMefSample/Pear.cs

@@ -0,0 +1,13 @@
+using System.Composition;
+
+namespace VSMefSample
+{
+    [Export(typeof(Fruit))]
+    [ExportMetadata("Type", "Pear")]
+    public class Pear : Fruit
+    {
+        public bool IsDelicious { get; set; }
+
+        public override string ToString() => $"Pear (IsDelicious: {this.IsDelicious})";
+    }
+}

VSMefSample/Program.cs

@@ -1,12 +1,49 @@
 using System;
+using System.Reflection;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.Composition;
 
 namespace VSMefSample
 {
     class Program
     {
         static void Main(string[] args)
         {
-            Console.WriteLine("Hello World!");
+            var exportProvider = CreateExportProviderAsync().GetAwaiter().GetResult();
+            Tree tree = exportProvider.GetExportedValue<Tree>();
+            var apple1 = (Apple)tree.CreateFruit("Apple");
+            apple1.IsJuicy = true;
+            var apple2 = (Apple)tree.CreateFruit("Apple");
+            var pear = (Pear)tree.CreateFruit("Pear");
+            pear.IsDelicious = true;
+
+            Console.WriteLine(tree);
+        }
+
+        static async Task<ExportProvider> CreateExportProviderAsync(CancellationToken cancellationToken = default(CancellationToken))
+        {
+            var discovery = new AttributedPartDiscovery(Resolver.DefaultInstance);
+            var parts = await discovery.CreatePartsAsync(Assembly.GetExecutingAssembly(), cancellationToken);
+            var catalog = ComposableCatalog.Create(Resolver.DefaultInstance)
+                .AddParts(parts);
+            var composition = CompositionConfiguration.Create(catalog);
+            composition.CreateDgml().Save("mefgraph.dgml");
+            if (!composition.CompositionErrors.IsEmpty)
+            {
+                foreach (var error in composition.CompositionErrors.Peek())
+                {
+                    Console.Error.WriteLine(error.Message);
+                    foreach (var part in error.Parts)
+                    {
+                        Console.Error.WriteLine("   " + part.Definition.Type.FullName);
+                    }
+                }
+            }
+
+            composition.ThrowOnErrors();
+            var exportProviderFactory = composition.CreateExportProviderFactory();
+            return exportProviderFactory.CreateExportProvider();
         }
     }
 }

VSMefSample/Tree.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Collections.Generic;
+using System.Composition;
+using System.Linq;
+using System.Text;
+
+namespace VSMefSample
+{
+    [Export]
+    public class Tree : IDisposable
+    {
+        private readonly List<Export<Fruit>> createdFruit = new List<Export<Fruit>>();
+
+        [ImportMany]
+        public List<ExportFactory<Fruit, FruitMetadata>> FruitFactories { get; set; }
+
+        public Fruit CreateFruit(string type)
+        {
+            ExportFactory<Fruit> fruitFactory = this.FruitFactories.Single(ff => ff.Metadata.Type == type);
+            Export<Fruit> export = fruitFactory.CreateExport();
+            this.createdFruit.Add(export);
+            return export.Value;
+        }
+
+        public override string ToString()
+        {
+            var sb = new StringBuilder();
+            sb.AppendLine("Tree");
+            foreach (var fruit in this.createdFruit)
+            {
+                sb.AppendLine($"   {fruit.Value}");
+            }
+
+            return sb.ToString();
+        }
+
+        public void Dispose() => this.Dispose(true);
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (disposing)
+            {
+                foreach (Export<Fruit> export in this.createdFruit)
+                {
+                    export.Dispose();
+                }
+
+                this.createdFruit.Clear();
+            }
+        }
+    }
+}

VSMefSample/VSMefSample.csproj

@@ -2,7 +2,12 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp2.0</TargetFramework>
+    <TargetFrameworks>net462</TargetFrameworks>
   </PropertyGroup>
 
+  <ItemGroup>
+    <PackageReference Include="Microsoft.VisualStudio.Composition" Version="15.3.38" />
+    <PackageReference Include="System.Composition" Version="1.1.0" />
+  </ItemGroup>
+
 </Project>

VSMefSample/mefgraph.dgml

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="utf-8"?>
+<DirectedGraph Layout="Sugiyama" GraphDirection="RightToLeft" xmlns="http://schemas.microsoft.com/vs/2009/dgml">
+  <Nodes>
+    <Node Id="VSMefSample_Pear" Label="VSMefSample.Pear" />
+    <Node Id="VSMefSample_Tree" Label="VSMefSample.Tree" />
+    <Node Id="Microsoft_VisualStudio_Composition_MetadataViewClassProvider" Label="Microsoft.VisualStudio.Composition.MetadataViewClassProvider" Category="VsMEFBuiltIn" />
+    <Node Id="VSMefSample_Apple" Label="VSMefSample.Apple" />
+    <Node Id="Microsoft_VisualStudio_Composition_PassthroughMetadataViewProvider" Label="Microsoft.VisualStudio.Composition.PassthroughMetadataViewProvider" Category="VsMEFBuiltIn" />
+    <Node Id="Microsoft_VisualStudio_Composition_ExportProvider_ExportProviderAsExport" Label="Microsoft.VisualStudio.Composition.ExportProvider.ExportProviderAsExport" Category="VsMEFBuiltIn" />
+  </Nodes>
+  <Links>
+    <Link Source="VSMefSample_Tree" Target="VSMefSample_Pear" />
+    <Link Source="VSMefSample_Apple" Target="VSMefSample_Tree" Category="ExportFactory" />
+    <Link Source="VSMefSample_Pear" Target="VSMefSample_Tree" Category="ExportFactory" />
+    <Link Source="VSMefSample_Tree" Target="VSMefSample_Apple" />
+  </Links>
+  <Categories>
+    <Category Id="Contains" IsContainment="True" />
+  </Categories>
+  <Styles>
+    <Style TargetType="Link" GroupLabel="ExportFactory">
+      <Condition Expression="HasCategory('ExportFactory')" />
+      <Setter Property="StrokeDashArray" Value="2,2" />
+    </Style>
+    <Style TargetType="Node" GroupLabel="VsMEFBuiltIn">
+      <Condition Expression="HasCategory('VsMEFBuiltIn')" />
+      <Setter Property="Visibility" Value="Hidden" />
+    </Style>
+  </Styles>
+</DirectedGraph>