Multiple Language RESX Resource Files

A large contribution today from Andrey Bushman, and a couple of upcoming Forge events:

Supporting Multiple Language Resource Files

Andrey Bushman raised another interesting issue in the Revit API discussion forum thread on why the '/language' key switches CurrentCulture instead of CurrentUICulture

In the course of our discussion, Andrey pointed out his highly interesting blog and shared a fully functional Revit add-in demonstrating how to support multi-language resources with all conceivable frills, bells and whistles:

If, like me, your command of Russian is limited, it helps to switch on automatic translation for the Russian blog :-)

By the way, this add-in obviously also makes use of Andrey's NuGet Revit API package, now updated to support the recent additional Revit 2017.X.Y releases.

Andrey's reason for raising the thread in the first place was a weird behaviour setting the UI culture in Revit 2017.1.1, which I passed on to the development team for further exploration.

However, Andrey provides a workaround for that too, in the module RevitPatches.cs:

span style="color:blue;">public static class RevitPatches
  /// <summary>
    /// This patch fixes the bug of localization switching
    /// for Revit 2017.1.1. It switches the 'Thread
    /// .CurrentThread.CurrentUICulture' and 'Thread
    /// .CurrentThread.CurrentCulture' properties according 
    /// the UI localization of Revit current session.
    /// </summary>
    /// <param name="lang">The target language.</param>
    public static void PatchCultures( LanguageType lang )
    if( !Enum.IsDefined( typeofLanguageType ), lang ) )
      throw new ArgumentExceptionnameof( lang ) );

    string language;

    switch( lang )
      case LanguageType.Unknown:
        language = "";
      case LanguageType.English_USA:
        language = "en-US";
      case LanguageType.German:
        language = "de-DE";
      case LanguageType.Spanish:
        language = "es-ES";
      case LanguageType.French:
        language = "fr-FR";
      case LanguageType.Italian:
        language = "it-IT";
      case LanguageType.Dutch:
        language = "nl-BE";
      case LanguageType.Chinese_Simplified:
        language = "zh-CHS";
      case LanguageType.Chinese_Traditional:
        language = "zh-CHT";
      case LanguageType.Japanese:
        language = "ja-JP";
      case LanguageType.Korean:
        language = "ko-KR";
      case LanguageType.Russian:
        language = "ru-RU";
      case LanguageType.Czech:
        language = "cs-CZ";
      case LanguageType.Polish:
        language = "pl-PL";
      case LanguageType.Hungarian:
        language = "hu-HU";
      case LanguageType.Brazilian_Portuguese:
        language = "pt-BR";
        // Maybe new value of the enum hasn't own 
        // `case`...
        throw new ArgumentExceptionnameof( lang ) );

    CultureInfo ui_culture = new CultureInfo( language );
    CultureInfo culture = new CultureInfo( language );

    Thread.CurrentThread.CurrentUICulture = ui_culture;
    Thread.CurrentThread.CurrentCulture = culture;

Here is a summary of our discussion consisting mainly of Andrey's explanation:

My external application (add-in) has two localizations: English (by default) and Russian. I now noticed that my external application (add-in) uses wrong localization on some computers. One of those computers has a 'clear' Revit without any other installed custom add-ins.

If I launch revit.exe with the /language RUS command line option, then the Revit UI is Russian, but my add-in UI still uses the default localization (i.e. "en") instead of "ru".

I extract the localized resources through the ResourcesManager class in my code. That is the native way to work with resources in .NET. I know that ResourcesManager chooses the localized resources based on the value of Thread.CurrentThread.CurrentUICulture.

Therefore, I assumed that this value isn't "ru" or "ru-RU", for some reason, despite the /language RUS key. I checked and confirmed that assumption (look my code below): the Thread.CurrentThread.CurrentUICulture property is set to "en" instead of "ru". Also, I see that Thread.CurrentThread.CurrentCulture uses "ru-RU" instead of "en".

Why does the /language key not switch the setting of Thread.CurrentThread.CurrentUICulture responsible for the user interface (UI)?

Is it bug?

Result IExternalApplication.OnStartup(
  UIControlledApplication application )
  // ...
  // I use the `/language RUS` key for revit.exe
  // But I see that my add-in user the 'default' 
  // localization instead of 'ru'. Hm...
  // Ok,I will check the CurrentCulture and 
  // CurrentUICulture  values...
  // Oops... Localization was changed by the 
  // `/language RUS` key, but not for that thread 
  // which shall to have this change! Why???

  CultureInfo n = Thread.CurrentThread.CurrentCulture; // ru-RU
  CultureInfo m = Thread.CurrentThread.CurrentUICulture; // en

  // I can fix this problem myself:
  // The CurrentUICulture switching fixes the 
  // problem, but why such problem occurs in Revit?

  CultureInfo k = new CultureInfo"ru" );
  Thread.CurrentThread.CurrentUICulture = k;

  // Now my add-in uses right localization. 

  // ...

Later, I found that this problem exists in Revit 2017.1.1, but this problem is absent in Revit 2017.

For demonstration of this problem I created the project and published it on bitbucket, in Andrey-Bushman/research_of_revit_culture_switching_problem.

You can fix this problem in Revit 2017.1.1 by using a class like this:

public sealed class UICultureSwitcher : IDisposable
  CultureInfo previous;

  public UICultureSwitcher()
    CultureInfo culture = new CultureInfoThread
      .CurrentThread.CurrentCulture.Name );

    previous = Thread.CurrentThread.CurrentUICulture;
    Thread.CurrentThread.CurrentUICulture = culture;

  void IDisposable.Dispose()
    Thread.CurrentThread.CurrentUICulture = previous;

Place code of methods of each external command and external application inside a using block with this class member initializing, and the problem will be fixed.

Expanded info and the patch are provided in the Russian blog post on Revit 2017.1.1.

I also created a multi-language add-in example, published in the RevitMultiLanguageAddInExample GitHub repository.

When you use the /language RUS key the UI of my add-in, its tooltip, expanded tooltip, and help file displayed on pressing F1 are in Russian.

When you use /language ENU key the UI of my add-in, its tooltip, expanded tooltip, and help file displayed on pressing F1 are in English.

The same applies for the TaskDialog content.

The expected correct behaviour is shown in the two-minute video on Revit lang bug:

Many thanks to Andrey for this beautiful and illuminating sample!

Creating and Using Localised Resource RESX Files

Andrey just published an eight-minute video tutorial on resx using explaining the simplest way to create and make use of localized add-in resources.

Additional information and expanded code examples are available from his Russian blog:

Upcoming Forge Accelerators

We have severalĀ Forge accelerators coming up in the next couple of months:

Upcoming Forge accelerators

I am planning on attending the two European ones and would love to see you there too.

Before that, however, the San Francisco accelerator provides the very next chance to attend – and the early bird gets the worm – so grab you chance while you can!

Bird with worm