Hi everyone,

I've been struggling with this for a while to no avail.

I have an internal application which uses remoting to
launch AppDomains and load/unload user assemblies. I'm
trying to integrate it with Visual Studio .NET as an add-
in. I've hit a rather major obstacle with using remoting
from an add-in, though, and boiled it down to a rather
simple test case:

using System;
using System.IO;

namespace ICLUBcentral.Example.AppDomainFailure {
   public abstract class CLI {
       public static void Main() {
           AppDomain ad = AppDomain.CreateDomain(
               "My First AppDomain");
           
           object remoteObj =
             ad.CreateInstanceFromAndUnwrap(
                 typeof(Dummy).Assembly.Location,
                 typeof(Dummy).FullName);
           
           Console.Out.WriteLine(
               "the proxy is of type ["
             + remoteObj.GetType().Assembly.FullName
             + "]" + remoteObj.GetType().FullName);
           
           Console.Out.WriteLine(
               "wish it were of type ["
             + typeof(Dummy).Assembly.FullName
             + "]" + typeof(Dummy).FullName);
           
           AppDomain.Unload(ad);
       
           Console.Out.Write("[press enter]");
           Console.Out.Flush();
           Console.In.ReadLine();
       }
   }
   
   public class Dummy : MarshalByRefObject {
       public Dummy() {
           //  Empty.
       }
       
       public string HelloWorld() {
           return "Hello, world.";
       }
   }
}

When I run that as an application, it works: The object
returned from CreateInstanceFromAndUnwrap is of the type I
asked for. When I run it from within a Visual Studio .NET
add-in (with the Console I/O replaced by MessageBox.Show,
say), remoteObject's type is System.MarshalByRefObject!
remoteObject's type should be a *subclass* of
MarshalByRefObject; it shouldn't be *exactly*
MarshalByRefObject! I don't know how to identify what's
different in the Visual Studio .NET execution environment
which would prevent this from working. Help, anyone?

The output of the above code (exactly) on the console is:

the proxy is of type [ICCTest, Version=1.0.1441.33463,
Culture=neutral, PublicKeyToken=null]
ICLUBcentral.Example.AppDomainFailure.Dummy
wish it were of type [ICCTest, Version=1.0.1441.33463,
Culture=neutral, PublicKeyToken=null]
ICLUBcentral.Example.AppDomainFailure.Dummy

The output from within my Visual Studio .NET add-in (with
console I/O replaced) is:

the proxy is of type [mscorlib, Version=1.0.3300.0,
Culture=neutral, PublicKeyToken=b77a5c561934e089]
System.MarshalByRefObject
wish it were of type [ICLUBcentral.Testing.VSAddIn,
Version=1.0.1441.33461, Culture=neutral,
PublicKeyToken=null]
ICLUBcentral.Example.AppDomainFailure.Dummy

(Sorry, the full source for an add-in would utterly
obfuscate the test. The above class should be pretty easy
invoke from one, though.)

Note: The behavior is the same with
CreateInstanceAndUnwrap (but I have to use AppDomainSetup
to set the search path, which makes the example longer).

Note also: Visual Studio .NET 2002 (upgrading soon).

--

Gordon Henriksen
IT Manager
ICLUBcentral Inc.
gordon@iclub.com