加载 ASP.NET Core MVC 5 项目的程序集时出现 FileNotFoundException

Question

I'm trying to explore an assembly that belongs to an ASP.NET Core MVC project. The project was made with .NET 5.

The problem is, when I try to explore the assembly's types, it throws a FileNotFoundException with the following message: Could not load file or assembly 'Microsoft.AspNetCore.Mvc.Core, Version=5.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. El sistema no puede encontrar el archivo especificado Could not load file or assembly 'Microsoft.AspNetCore.Mvc.Core, Version=5.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. El sistema no puede encontrar el archivo especificado .

Issuing a dotnet build command compiles the project without problems.

Exploring the corresponding.csproj file, I found that the Microsoft.AspNetCore.Mvc.Core dependency is not declared in the project file, but the SDK indicated in the project file's XML root is Microsoft.NET.Sdk.Web , and I understand that marks the project as an ASP.NET Core project, but I can't find a way to bring the necessary dependencies to load the assembly.

Code as follows.

Code that loads the assembly:

var reader_context = new ReaderLoadContext(artifact_dir);
var assembly_path = ""; //Path of the compiled assembly
var assembly = reader_context.LoadFromAssemblyPath(assembly_path);
//Here's where it crashes
var target_types = assembly.ExportedTypes.Where(t => t.BaseType != null && t.BaseType.Name == "ControllerBase").ToArray();

ReaderLoadContext 's code:

public class ReaderLoadContext : AssemblyLoadContext
{
    private AssemblyDependencyResolver _resolver;

    public ReaderLoadContext(string readerLocation)
    {
        _resolver = new AssemblyDependencyResolver(readerLocation);
    }

    protected override Assembly Load(AssemblyName assemblyName)
    {
        var assembly_path = _resolver.ResolveAssemblyToPath(assemblyName);
        if (assembly_path != null)
        {
            return LoadFromAssemblyPath(assembly_path);
        }

        return null;
    }

    protected override IntPtr LoadUnmanagedDll(string unmanagedDllName)
    {
        var library_path = _resolver.ResolveUnmanagedDllToPath(unmanagedDllName);
        if (library_path != null)
        {
            return LoadUnmanagedDllFromPath(library_path);
        }
        return IntPtr.Zero;
    }
}

Answer 1

Turns out this is a known limitation of AssemblyLoadContext and one of the solutions (more like an ugly workaround) is to add a reference to the missing framework in the application that explores the desired assembly. I added a PackageReference item in my app's.csproj file and now it properly loads the assembly I want to scan.

I don't know if I should mark this as an answer. In one hand, it does what I need it to. OTOH, it forces the developer to add all possible framework references beforehand just in case, and if Microsoft (or a 3rd party) releases another framework, it requires releasing a new version of the app.

So hopefully someone knows a more elegant solution.

Thanks to @deepak-msft and everyone else for the help.