Getting custom assembly attributes without loading into current AppDomain

Question

I have created a small application to recursively load assemblies in a provided directory and read their custom attributes collection. Mainly just to read the DebuggableAttr

Answer 1

You need to use Assembly.ReflectionOnlyLoad.

Here are some MSDN Notes that shows how to use it:

using System;
using System.IO;
using System.Reflection;

public class ReflectionOnlyLoadTest
{
    public ReflectionOnlyLoadTest(String rootAssembly) {
        m_rootAssembly = rootAssembly;
    }

    public static void Main(String[] args)
    {
        if (args.Length != 1) {
            Console.WriteLine("Usage: Test assemblyPath");
            return;
        }

        try {
            ReflectionOnlyLoadTest rolt = new ReflectionOnlyLoadTest(args[0]);
            rolt.Run();
        }

        catch (Exception e) {
            Console.WriteLine("Exception: {0}!!!", e.Message);
        }
    }

    internal void Run() {
        AppDomain curDomain = AppDomain.CurrentDomain;
        curDomain.ReflectionOnlyPreBindAssemblyResolve += new ResolveEventHandler(MyReflectionOnlyResolveEventHandler);
        Assembly asm = Assembly.ReflectionOnlyLoadFrom(m_rootAssembly);

        // force loading all the dependencies
        Type[] types = asm.GetTypes();

        // show reflection only assemblies in current appdomain
        Console.WriteLine("------------- Inspection Context --------------");
        foreach (Assembly a in curDomain.ReflectionOnlyGetAssemblies())
        {
            Console.WriteLine("Assembly Location: {0}", a.Location);
            Console.WriteLine("Assembly Name: {0}", a.FullName);
            Console.WriteLine();
        }
    }

    private Assembly MyReflectionOnlyResolveEventHandler(object sender, ResolveEventArgs args) {
        AssemblyName name = new AssemblyName(args.Name);
        String asmToCheck = Path.GetDirectoryName(m_rootAssembly) + "\\" + name.Name + ".dll";
        if (File.Exists(asmToCheck)) {
            return Assembly.ReflectionOnlyLoadFrom(asmToCheck);
        }
        return Assembly.ReflectionOnlyLoad(args.Name);
    }

    private String m_rootAssembly;
}