如何使用System.Reflection.Metadata查找实现特定接口的所有类

Question

我试图弄清楚是否能够可靠地识别包含实现特定接口的类的.NET程序集。这里的问题是，我不能使用反射加载程序集，因为这需要解析要加载的程序集的所有引用，在我的情况下这是不可能的。

这就是为什么我试图使用NuGet包System.Reflection.Metadata来这样做的原因，因为这种方法似乎不需要加载引用的程序集。但是，我不得不完成代码，以便找到所讨论的接口。我现在拥有的是：

namespace ReflectionMetadataTest
{
   using System;
   using System.IO;
   using System.Reflection.Metadata;
   using System.Reflection.PortableExecutable;

   public static class Program
   {
      static int Main(string[] args)
      {
         if (args.Length < 1)
         {
            Console.Error.WriteLine("Please specify a single file path.");
            return 1;
         }

         string filePath = new FileInfo(args[0]).FullName;

         using (var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
         {
            using (var peReader = new PEReader(fileStream))
            {
               if (!peReader.HasMetadata)
               {
                  return 2;
               }

               MetadataReader metadataReader = peReader.GetMetadataReader();

               foreach (var typeDefinitionHandle in metadataReader.TypeDefinitions)
               {
                  var typeDefinition = metadataReader.GetTypeDefinition(typeDefinitionHandle);
                  var interfaceHandles = typeDefinition.GetInterfaceImplementations();

                  foreach (var interfaceHandle in interfaceHandles)
                  {
                     var interfaceImplementation = metadataReader.GetInterfaceImplementation(interfaceHandle);
                     var whateverThatIs = interfaceImplementation.Interface;

                     // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
                     // TODO: How would I find the fully qualified name of the the interface so that I can compare with the name I'm looking for?
                     // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
                  }
               }

               return 0;
            }
         }
      }
   }
}

如何将whateverThatIs解析为完全限定名的实际类型，以便将其与我要寻找的接口的类型/名称进行比较？

Answer 1

好的，经过更多的尝试和错误之后，我可以找到程序集实现中的所有类的完全限定名：

namespace ReflectionMetadataTest
{
   using System;
   using System.IO;
   using System.Reflection.Metadata;
   using System.Reflection.PortableExecutable;

   public static class Program
   {
      static int Main(string[] args)
      {
         if (args.Length < 1)
         {
            Console.Error.WriteLine("Please specify a single file path.");
            return 1;
         }

         string filePath = new FileInfo(args[0]).FullName;

         using (var fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
         {
            using (var peReader = new PEReader(fileStream))
            {
               if (!peReader.HasMetadata)
               {
                  return 2;
               }

               MetadataReader metadataReader = peReader.GetMetadataReader();
               Console.WriteLine($"The file \"{filePath}\" {(metadataReader.IsAssembly ? "*is*" : "is *not*")} an assembly.");

               foreach (var typeDefinitionHandle in metadataReader.TypeDefinitions)
               {
                  var typeDefinition = metadataReader.GetTypeDefinition(typeDefinitionHandle);
                  var typeName = metadataReader.GetString(typeDefinition.Name);
                  Console.WriteLine(typeName);
                  var interfaceHandles = typeDefinition.GetInterfaceImplementations();

                  foreach (var interfaceHandle in interfaceHandles)
                  {
                     var interfaceImplementation = metadataReader.GetInterfaceImplementation(interfaceHandle);
                     var interfaceType = interfaceImplementation.Interface;

                     if (interfaceType.Kind == HandleKind.TypeReference)
                     {
                        var typeReferenceHandle = (TypeReferenceHandle)interfaceType;
                        var typeReference = metadataReader.GetTypeReference(typeReferenceHandle);
                        var namespaceName = metadataReader.GetString(typeReference.Namespace);
                        var interfaceName = metadataReader.GetString(typeReference.Name);
                        Console.WriteLine($"  Interface Name: {namespaceName}.{interfaceName}");
                     }
                  }
               }

               return 0;
            }
         }
      }
   }
}