Please share more details about IResourceManager & ResourceManagerRequested

[Jack251970]

Office document has provided these sample codes:

ResourceManagerRequested += (_, e) =>
 {
    // CreateResourceManager() is a custom method you
    // create that returns an instance of IResourceManager.
    IResourceManager resourceManager = CreateResourceManager();
    e.ResourceManager = resourceManager;
 };

But I am still confused about how to get a custom IResourceManager instance.

IResourceManager has one property related to the resources only - ResourceMap MainResourceMap.

For ResourceMap, it is a sealed class without public function to add & delete its resources. Similarly, ResourceManager is also a sealed class and can only load one resource file. It seems that I cannot manage its resources and the IResourceManager instance I can get is either the default application resources or the resources in one resource file (from ResourceManager).

Now, I want to get a IResourceManager instance, which contains not only the default application resources but also the resources in one resource file. How can I do that?

[castorix]

Theorically it should be by implementing a class like
public class CustomResourceManager : IResourceManager
by adding mainly
public ResourceMap MainResourceMap (with get{}, it is called many times at beginning if I put a BP (I returned _resourceManager.MainResourceMap))
and
ResourceContext IResourceManager.CreateResourceContext()
where I tried to test by overriding the scale like:

private ResourceManager _resourceManager;

in constructor :
_resourceManager = new ResourceManager();
then in CreateResourceContext

 var resourceContext = _resourceManager.CreateResourceContext();
resourceContext.QualifierValues["Scale"] = "200";
 return resourceContext;

but it changed nothing...