Comments on: Powershell: Load assembly without locking file.

By: James

James — Thu, 31 Dec 2009 00:37:21 +0000

What happens if the assembly you are loading depends on types defined in another assembly that has not yet been loaded?

I seem to recall I had issues with this when I did the workaround of loading a byte array in the past.

By: Keith Hill

Keith Hill — Tue, 29 Dec 2009 00:01:43 +0000

Here’s a simpler way to read a file’s bytes: $bytes = [io.file]::ReadAllBytes($path)

By: Jason Jarrett

Jason Jarrett — Wed, 23 Dec 2009 13:43:54 +0000

@Rennie – I can’t say I know exactly how powershell was handling the loading of multiple dll’s into the same session. I did, however, notice that it was picking up the new “version” every time my build ran and did not get the “cannot load assembly because it already exists in the app domain” exception.

Thanks to @Martin, my get-assembly-version has been updated with his great suggestion.

By: Martin

Martin — Wed, 23 Dec 2009 09:04:58 +0000

If it’s just for getting the assembly version you could also use

[System.Reflection.AssemblyName]::GetAssemblyName(string file)

It opens, reads and closes the assembly to get the version information, but does not add it to the app domain.

By: Rennie

Rennie — Wed, 23 Dec 2009 08:21:28 +0000

I too once ran into the problem that .Net does not have an Unload assembly function. I ended up spawning a new process to do the load of the assembly and examine it, and then let that process die.

With your technique the assembly remains loaded, I assume.

1. This can have storage implications – if you need to do this for hundreds or thousands of assemblies you’ll run out of storage, right?

2. In a product build situation where you build an assembly and want to load it and examine the result, and then maybe rebuild it and re-load it, I’m wondering what will happen the second time you try to load it and the previous copy is still loaded?

Thanks for the article.