Remove BinaryFormatter uses

[vatsan-madhavan]

Related:
https://github.com/dotnet/corefx/issues/38760

BinaryFormatter will be removed in .NET 5. Remove its uses with whatever drop-in replacement is provided in .NET 5.

[weltkante]

Note that this will break drag'n'drop and clipboard comatibility with desktop framework applications for nontrivial content, unless the replacement is able to produce/consume the same binary data.

[jonko0493]

Looks like this ended up getting punted to the .NET 7 timeline. We're now in .NET 8, though, and this is causing crashes in some applications that rely on WPF (see picoe/Eto#2607). Is there a plan to address this issue beyond just telling applications to use an insecure serializer?

[weltkante]

As far as I'm aware WinForms hasn't switched away from BinaryFormatter clipboard/drag'n'drop usage either, they seem to have pushed it to .NET 9 issue search link. So no, at the moment there is nothing, I would expect WinForms to make this step before WPF since they are usually more active. Its unfortunate that the core/runtime guys are overly eager to warn (and possibly break) people before things are ready.

[jonko0493]

Thanks for the reply @weltkante. That makes sense -- for now I suppose we'll just have to disable that break until at least .NET 9. Appreciate the help!

[Symbai]

FYI: Deadline has been set dotnet/runtime#98245