This sample project demonstrates how to localize the user interface. First of all, use StiOptions.Localization.Load() method to load localization file:

private void LoadLocalization()
{
	var fileName = (string)((Label)ComboBoxLocalizations.SelectedItem).Content;
	StiOptions.Localization.Load(fileName);
}

...

Then, use LoadLocalization() method to localize the user interface:

...

private void ButtonShow_Click(object sender, RoutedEventArgs e)
{
	LoadLocalization();

	var report = new StiReport();
	report.Load(@"Reports\SimpleList.mrt");
	report.ShowWithWpf();
}

private void ButtonDesign_Click(object sender, RoutedEventArgs e)
{
	LoadLocalization();

	var report = new StiReport();
	report.Load(@"Reports\SimpleList.mrt");
	report.DesignV2WithWpf();
}

In the screenshot below you can see the result of the sample code: