Embedding multiple, identically named resource (RC) files in a native DLL

Question

Hi all,

For my application (an MMC snap-in) I need to create a single native DLL containing strings that are localized into different languages. In other words, if you were to inspect this DLL with Visual Studio, you would see multiple string tables, each associated with a different locale but containing the same string IDs.

The approach I would like to take is to have various subdirectories under my project directory such as "de", "en", "es", etc (i.e. one for each language). Inside each subdirectory would be a file called "Resources.rc" which would be the RC file containing the strings for that language. Having my resources in this structure would be ideal for the localisation team.

I have managed to create my various RC files and have added them to my Visual C++ project. They all appear correctly in Solution Explorer in Visual Studio (you basically see five instances of an entry called "Resource.rc", but each entry points to a different file).

The problem comes with building my project. It seems that only a single one of the RC files (the one that is specified first in the vcproj file) is compiled into a RES file and included into my DLL. Presumably this is because Visual Studio does not like the fact that the RC files all have the same name.

Is there any way to achieve what I want?

Thanks!

Answer 1

Yes. And No. If you want multiple RC files you are going to have to leverage off the Operating systems support to have multiple resources in one file. In the resource editor, for each resource, you can set its locale AND the resource editor will allow you to have multiple resources with the same ID, as long as their locale is different.

So, your first step would be to edit each of the RC files to ensure that the resources in one are English/US, another contains French etc.

Next, get the main RC file to #include the others.

Lastly, and this is the problem, you need to rely on the Operating systems logic to load the correct resources. If you are happy to let the locale of the PC determine what UI language is used you have done enough.

If you want to provide a menu option allowing users to change languages: SetThreadLocale used to be an easy way to switch the Locale of loaded resources on the current thread. Since Windows 2000 some unfortunate overloaded usage of the API has caused MS to deprecate its usage in favor of requiring App Developers to always use FindResourceEx - which really doesn't help you if you want, for example, to load a string from a string table.

If you really want an easy way to have a user selectable UI language, then you need to place each of your .rc files into a seperate dll. and then LoadLibrary on the appropriate language resource dll.