private void OnClickOk(object sender, RoutedEventArgs e)
        {
            int howMany = 0;

            if (!NumbersOfNewCategories.IsValid)
            {
                return;
            }
            if (NumbersOfNewCategories.Text == "")
            {
                NumbersOfNewCategories.IsValid = false;
            }

            try
            {
                howMany = Convert.ToInt32(NumbersOfNewCategories.Text);
            }
            catch (FormatException)
            {
                NumbersOfNewCategories.Text = String.Empty;
                return;
            }
            ConditionCategoryControlViewModel data = (ConditionCategoryControlViewModel)DataContext;

            if (data != null)
            {
                data.ReorganizeSubcategories(howMany);
            }
        }
 private void UserControl_Loaded(object sender, RoutedEventArgs e)
 {
     if (_isNewInstance)
     {
         NumbersOfNewCategories.ValidationRule = new RegexValidationRule("^\\d+$");
         ConditionCategoryControlViewModel dataContext = (ConditionCategoryControlViewModel)DataContext;
         MessageView.AssignYesNoMessage(dataContext.MessageBox);
     }
     _isNewInstance = false;
 }