private void GetClassStudents()
{
StoreDB db = new StoreDB();
try
{
DataItems = db.GetClassStudents();
}
catch (Exception e)
{
log.Error("In CSViewModel..GetClassStudents: " + e.StackTrace);
Environment.Exit(-1);
}
//https://wpftutorial.net/DataViews.html
//https://stackoverflow.com/questions/8597824/listbox-groupstyle-display-how-to-design-a-group-name
//https://stackoverflow.com/questions/20188132/how-to-correctly-bind-update-a-datagrid-with-a-collectionviewsource
//The sorting technique explained above is really simple, but also quite slow for a large amount of data,
//because it internally uses reflection. But there is an alternative, more performant way to do sorting by providing a custom sorter.
//when DataItems points to a new object, we need to GetDefaultView(DataItems) and add Grouping
//CSSelectionView ItemsSource="{Binding DataItems}"; We dont need to bind to DataItems1
_customerView = CollectionViewSource.GetDefaultView(DataItems);
if (_customerView.GroupDescriptions == null || _customerView.GroupDescriptions.Count == 0)
{
_customerView.GroupDescriptions.Add(new PropertyGroupDescription("Grouping"));
_customerView.SortDescriptions.Add(new SortDescription("Grouping", ListSortDirection.Ascending));
_customerView.SortDescriptions.Add(new SortDescription("StudentName", ListSortDirection.Ascending));
}
if (db.hasError)
{
App.Messenger.NotifyColleagues("SetStatus", db.errorMessage);
}
}
