How Do I refresh window in wpf?

Maybe:

this.NavigationService.Refresh();

or

this.NavigationService.Navigate(new Uri("<EnterPage name here.xaml", UriKind.Relative));

I used this workaround, it's no perfect but works

MainWindow newWindow = new MainWindow();
Application.Current.MainWindow = newWindow;
newWindow.Show();
this.Close();

Is the list an ObservableCollection or properties implementing INotifyPropertyChanged?

Have you tried:

myDatagrid.Items.Refresh();