Deserialization Problem solved!

I have been working on COM interop project to allow access to Google Blogger and Picasa API from a Visual Basic 6.0 App. I know I know, why let go of the past and write a modern app perhaps in WPF..., I have my reasons.

Blogger Solution
COM Interop Project
Google API Project
Test UI Project

VB6 Project
Referencing COM Interop type Library

My solution is written in C#, 2.0 Framework (trying to still support Windows 2000, again I know I know let go of the past...) Added a Test windform project to the solution so I can run UI tests without COM. Worked great!

Created my COM interop project, something I had not done before. It seemed to work fine.

Then I decided I needed to serialize objects to cache downloaded album and images to spend up locating an online image. Worked well in C# except, when deserializing objects kept throwing errors when run from COM from my VB6 project. Two errors, Unable to find file (Assembly DLL) and unable to load type. Puzzled, I googled for a solution, WOW what a fine mess binary deserialization can be!

After several failed attempts, I found the solution:
1) Could not run my VB6 project and get the deserialization to work. Compiled the exe and...
2) Created an App.Config and renamed after my VB6 project exe: MyProject.exe.Config
3) In the App.Config, In the runtime section, I added for each of assemblies.

Now I can run my COM Interop project from VB6 and deserialization does not throw errors. At some point I am going to try to actually understand why this works but right now my goal is simply a working pattern that I can successfully produce.

Key my solution came when I enabled Fusion logging so I could see why was happening as my code loaded or tried to load assemblies needed for deserialization.

How to use App.Config with COM interop

From Beth Massi's blog:

Using My.Settings and WCF Configuration with the Interop Forms Toolkit

Fun with Deserialization

More fun serialization, this time with deserialization.

Currently working on a .net project whose feature set will allow my to replace some older third party libraries used in a VB6 project that do not work properly under Vista 64bit edition.

Things that I have successfully completed:

• Replaced Microsoft IE6 era Web browser control with a .net webbrowser control in a winform.
  
• Replaced functionality of Microsoft Internet transfer control to download online files.
• Successfully extended Google Picasa API and Blogger API to VB6 through COM interop type library
• Successfully implemented binary serialization of Picasa and Blogger caching the data locally.
  

DRCWinformUI.DLL - COM Interop assembly exposing methods/events for use in VB6 project
PicasaBloggerUserControls.DLL - .net 2.0 framework

Now to the problem: Deserialization:

Implemented code to de-serialize objects, which works fine in .net test app, but fails over COM:
SerializationException: Cannot find assembly...

Found the following articles:
Excellent article from http://spazzarama.wordpress.com/ describing the exact same problem:

C# – BinaryFormatter.Deserialize is “Unable to find assembly”

Documentation for SerializationBinder Class

I must give props to a co-worker Tom G. who pointed me in the correct direction of properly resolving the assembly by name. A problem that was solved at work on another project.