ILocalize Sample

App.xaml.cs

public partial class App : PrismApplication
{
    protected override void OnInitialized()
    {
        var localize = Container.Resolve<ILocalize>();
        localize.RegisterManager(CoreAppResources.ResourceManager);
        
        // If you don't want to use the current UI Culture
        localize.SetCulture(new CultureInfo("es");
    }

    protected override void RegisterTypes(IContainerRegistry containerRegistry)
    {
        containerRegistry.RegisterSingleton<ILocalize, ResxLocalize>();
    }
    
    protected override void ConfigureModules(IModuleCatalog moduleCatalog)
    {
        moduleCatalog.AddModule<ModuleA>();
        moduleCatalog.AddModule<ModuleB>();
    }
}

ModuleA.cs

public class ModuleA : IModule
{
    private ILocalize _localize { get; }
    
    public ModuleA(ILocalize localize)
    {
        _localize = localize;
    }
    
    public void OnInitialized(IContainerProvider containerProvider)
    {
        localize.RegisterManager(ModuleAResources.ResourceManager);
    }
}

SomeViewModel.cs

public class SomeViewModel
{
    public SomeViewModel(ILocalize localize)
    {
        LocalizedString = localize["SomeKey"];
    }

    public string LocalizedString { get; }
}