public async void load_data_once_comboboxes(ComboBox comboBox, string query, string key, string value, int selected_value)
        {
            CurtainDesigner.Models.Classes.MCManage <L>             model = new CurtainDesigner.Models.Classes.MCManage <L>();
            CurtainDesigner.Views.Classes.MCViewManage <O, L, F, T> view  = new CurtainDesigner.Views.Classes.MCViewManage <O, L, F, T>();
            SqlDataReader reader = null;

            reader = await model.getDataFromDB(query);

            view.loadDataFromDB_comboboxes(comboBox, reader, new System.ComponentModel.BindingList <KeyValuePair <string, int> >(), key, value, selected_value);
        }
        public async void load_installations(F form)
        {
            CurtainDesigner.Models.Classes.MCManage <L>             model = new CurtainDesigner.Models.Classes.MCManage <L>();
            CurtainDesigner.Views.Classes.MCViewManage <O, L, F, T> view  = new CurtainDesigner.Views.Classes.MCViewManage <O, L, F, T>();
            SqlDataReader reader = null;

            reader = await model.getDataFromDB($"Select * From [Installation];");

            view.loadDataFromDB_comboboxes((form as CurtainDesigner.OrderForms.FormMCOrder).comboBoxInstallation, reader, new System.ComponentModel.BindingList <KeyValuePair <string, int> >(), "Price", "Installation_id");

            model.closeConnection();
        }
        public async void load_data(F form)
        {
            CurtainDesigner.Models.Classes.MCManage <L>             model = new CurtainDesigner.Models.Classes.MCManage <L>();
            CurtainDesigner.Views.Classes.MCViewManage <O, L, F, T> view  = new CurtainDesigner.Views.Classes.MCViewManage <O, L, F, T>();
            SqlDataReader reader = null;

            reader = await model.getDataFromDB("Select * From [MC_types];");

            view.loadDataFromDB_comboboxes((form as CurtainDesigner.OrderForms.FormMCOrder).comboBoxCurtainType, reader, new System.ComponentModel.BindingList <KeyValuePair <string, int> >(), "Type_name", "Type_id");

            reader = await model.getDataFromDB($"Select * From [MC_Additional_equipment];");

            view.loadDataFromDB_comboboxes((form as CurtainDesigner.OrderForms.FormMCOrder).comboBoxEquipment, reader, new System.ComponentModel.BindingList <KeyValuePair <string, int> >(), "Equipment", "Equipment_id");

            reader = await model.getDataFromDB("Select * From [System_color];");

            view.loadDataFromDB_comboboxes((form as CurtainDesigner.OrderForms.FormMCOrder).comboBoxSystemColor, reader, new System.ComponentModel.BindingList <KeyValuePair <string, int> >(), "Name", "Color_id");

            reader = await model.getDataFromDB($"Select * From [Installation];");

            view.loadDataFromDB_comboboxes((form as CurtainDesigner.OrderForms.FormMCOrder).comboBoxInstallation, reader, new System.ComponentModel.BindingList <KeyValuePair <string, int> >(), "Price", "Installation_id");

            model.closeConnection();
        }