Sets the specified language for the current application when called before the application windows are shown.
A string value representing the name of the language that must be used in the application.
XAF application uses the language specified by the IModelApplication.PreferredLanguage property of the Application Model's IModelApplication node (see Localization Basics). To set another language during application startup, use the SetLanguage method. The method assigns the languageName parameter value to the PreferredLanguage property. So, the specified language will be used even after the application is restarted.
See the SetFormattingCulture article for an example.
XAF applications are not designed to switch the language during application execution.