public CategoryManager(CategoryManagerController controller)
        {
            this.Controller = controller;
            InitializeComponent();
            RefreshComboBox();

            //categoryComboBox.SelectedItem = null;
            //subcategoryComboBox.SelectedItem = ;
        }
 public void OpenCategoryManager()
 {
     this.CategoryManagerController = new CategoryManagerController();
     this.CategoryManager           = new CategoryManager(this.CategoryManagerController);
 }