private void EmployeeFill() { DBTables dbTables = new DBTables(); Action action = () => { try { dbTables.DTEmployee.Clear(); dbTables.DTTrainDriverFill(); dbTables.dependency.OnChange += ChangeEmployee; cbTrainDriver.DataSource = dbTables.DTEmployee; cbTrainDriver.ValueMember = "ID_employee"; cbTrainDriver.DisplayMember = "Name_Driver"; cbTrainDriver.SelectedValue = -1; } catch (Exception ex) { MessageBox.Show(ex.Message); } }; Invoke(action); }