One of the more annoying things about the way .Net is handling assemblies is the load context. If you load an assembly using Assembly.LoadFile(), it will not be available if you then do Assembly.Load().
There are any number of scenarios where this is a major hurdle. Any kind of plug in architecture, for instance. After getting bit by this when I wrote NHibernate Query Analyzer, I know way too much about resolving assemblies and the problems that this entails.
It can get much worse when you try to load assemblies from locations that are not in your private bin path. Anyway, I put together a small class that will fix this issues for me.
public static class AssemblyLocator
static Dictionary<string, Assembly>assemblies;
public static void Init()
assemblies = new Dictionary<string, Assembly>();
AppDomain.CurrentDomain.AssemblyLoad += new AssemblyLoadEventHandler(CurrentDomain_AssemblyLoad);
AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(CurrentDomain_AssemblyResolve);
static Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args)
Assembly assembly = null;
assemblies.TryGetValue(args.Name, out assembly);
static void CurrentDomain_AssemblyLoad(object sender, AssemblyLoadEventArgs args)
Assembly assembly = args.LoadedAssembly;
assemblies[assembly.FullName] = assembly;
As you can see, all you need to do is to call AssemblyLocator.Init(), and it will make sure that any assembly, not matter how it was loaded, will be accessible via Assembly.Load() and friends.