I'm grouping my grid like this:
ListCollectionView collection = new ListCollectionView(_ActionCollection);
collection.GroupDescriptions.Add(new PropertyGroupDescription("InvoiceNumber"));
dataGrid1.ItemsSource = collection;
Now I want to get the sum of the items which are grouped.
For example:
If grouped ivnoice number 231 and 245 contain both 3 rows, how can I get the sum for the example id?