Access Resources from Externally-Created .resx File

Question

My main Windows Forms (managed C++) project has a class that presents an image with tiles that can be shown or hidden to create a responsive diagram.

I created a separate utility app that helps me get all the images positioned correctly, etc. This app is written in C# and writes a .resx file containing the image data and positioning, using the following code snippet:

using(ResXResourceWriter resx = new ResXResourceWriter(sfd.FileName)) {
    resx.AddResource("Size", canvas.Size);
    List<int> IDs = canvas.IDs;
    resx.AddResource("IDList", IDs);
    resx.AddResource("BackgroundIndex", canvas.BackgroundIndex);
    foreach(int id in IDs) {
        String positionKey = String.Format("Position.id{0}", id);
        String visibilityKey = String.Format("Visibility.id{0}", id);
        String imageKey = String.Format("Image.id{0}", id);
        resx.AddResource(imageKey, canvas.TileImage(id));
        resx.AddResource(positionKey, canvas.TilePosition(id));
        resx.AddResource(visibilityKey, canvas.TileVisible(id));
    }
}

I can open the .resx file in a text editor and see that it is well-formed and contains the expected data.

Then I take that .resx file and add it to my main application's project. Now I can't figure out how to get at the resources inside it. The code I've tried is:

ResourceManager ^ image_rm = gcnew ResourceManager(
    "resx_file_name_without_extension", GetType()->Assembly);
ResourceSet ^ image_rs = image_rm->GetResourceSet(
    System::Globalization::CultureInfo::CurrentCulture, true, true);

At runtime, the second line (the GetResourceSet call) throws a System.Resources.MissingManifestResourceException with the following message text:

Resource load failure: Could not find any resources appropriate for the specified culture or the neutral culture. Make sure "resx_file_name_without_extension.resources" was correctly embedded or linked into assembly "my_assembly" at compile time, or that all the satellite assemblies required are loadable and fully signed.

I suspect my problem is...well I don't really know. Maybe I'm not using the right identifier in the ResourceManager constructor. I tried explicitly setting "Excluded From Build: No" and "Content: Yes" in the file's properties, but that had no effect.

Is it even possible to drop an externally-created .resx file into a project and get at the resources within? I definitely need it compiled in; I can't ship a product with dangling .resx files. I can always create a set of static data objects in .cpp files, but the .resx approach seemed more elegant...

score 0 · Accepted Answer · answered Sep 25 '17 at 14:18

Turns out a comment on this unanswered question was the secret sauce. Prepending the root namespace to the identifier made the ResourceManager happy:

ResourceManager ^ image_rm = gcnew ResourceManager(
    "my_root_namespace.resx_file_name_without_extension", GetType()->Assembly);
ResourceSet ^ image_rs = image_rm->GetResourceSet(
    System::Globalization::CultureInfo::CurrentCulture, true, true);

Just how or why the compiler decided to place the resources within that namespace is still a bit of a mystery to me, but that's trivia for another day.

The question to which I link involves a .resx created with VS within the project, and mine involves adding one created externally, so I think it's a different-enough situation to warrant a separate Q/A.

Access Resources from Externally-Created .resx File

1 Answers1