private void worker_DoWork(object sender, DoWorkEventArgs e)
        {
            EmployeeFactory EFobj = new EmployeeFactory();

            this.Dispatcher.Invoke(new Action(delegate
            {
                EmployeeGrid.ItemsSource = EFobj.GetAll();
            }));
        }
        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            EmployeeFactory          obj  = new EmployeeFactory();
            List <EmployeeViewModel> list = obj.GetAll();

            this.Dispatcher.Invoke(new Action(delegate
            {
                cbEmployee.ItemsSource       = list;
                cbEmployee.DisplayMemberPath = "E_Name";
                cbEmployee.SelectedValuePath = "E_ID";
            }));
        }