Localization with SharpDevelop

// load the resource file once
resourceManager = ResourceManager.CreateFileBasedResourceManager(file, filePath, null);

// depending on user selection, I set the CultureInfo in the code behind the form, i.e.
Thread.CurrentThread.CurrentUICulture = locales[0];   // which contains "en"

// and that's the method of the same class used to lookup the values
public string getValue ( string key )
{
    return resourceManager.GetString(key);
}