Hi

my english is not so good but i try my best. 

 I use the DataGridVirtualizingCollectionViewSource for lazy loading and show the Result in an TableView. When i click on the Header for sorting the Data, than nothing changes. The basic Problem i think is, the Application don't know that it must collect sorted data for the View.It takes everytime the same Data. After the Click my Method xx_QueryItems()  runs. But i can't find an propertie that says me -> "give me Data for an sorted View".

How can i sort this type of DataGrid ?

If posible plz give me an example. thx.

 Alex

 

For sorting on a custom or user defined objects, you should implement your own Sorting mechanism as already described in the online documentation at the page: http://doc.xceedsoft.com/products/XceedWpfDataGrid/Sorting_Data.html.

The example 5 should help you address your issue.

 

 

 

---

Xceed - Software Developer and Technical Support

Thx for your Answer but it didn't work.

I wrote my own Comparer-Class and set the "SortComparer" Property like Xceed did it in Example 5. For debug i set an Breakpoint at my Comparer-Class but at Runtime it was never used.

Code:

 DataGridItemProperty oItemProperty = new DataGridItemProperty();
                    oItemProperty.Name = oViewField.FieldName;
                    oItemProperty.Title = oViewField.Caption;
                    oItemProperty.DataType = cvf.LastFieldProperty.DataType;
                    oItemProperty.CalculateDistinctValues = oViewField.DistinctValues;
                    oItemProperty.SortComparer = new StringComparer();

  this.ViewSource = new DataGridVirtualizingCollectionViewSource();
            this.ViewSource.QueryItems += new EventHandler<QueryItemsEventArgs>(DataGridVirtualizingCollectionViewSource_QueryItems);
            this.ViewSource.QueryItemCount += new EventHandler<QueryItemCountEventArgs>(DataGridVirtualizingCollectionViewSource_QueryItemCount);
            this.ViewSource.AutoCreateItemProperties = false;
            this.ViewSource.AutoFilterMode = AutoFilterMode.And;
// Bind the DataGrid to the DataGridControl
            Binding b = new Binding() { Source = this.ViewSource };
            this.dgc.SetBinding(DataGridControl.ItemsSourceProperty, b);

 

Do i something wrong?

The StringComparer class is an abstract class and therefore cannot be instantiated. You will need to use one of its derived classes or provide your own IComparer implementation, as demonstrated in the example Mohamed referenced.

If you use the AddressComparer class demonstrated in the example and provide it to a DataGridItemProperty that contains strings, are you able to sort the columns? 

Do you have any errors in the output window? 

---

Senior Technical Writer
- Xceed Software

In three words I can sum up everything I've learned about life: it goes on.

I'm sorry but you misunderstand my Post. I took the Quellcode of the AddressComparer and changed it to StringComparer. It has nearly the same code. No change no error at Runtime.

 

My apologies. When using the DataGridVirtualizingCollectionViewSource, sorting is not done locally, it is done in the server; therefore, the custom sort comparer will never be used.

I will update the documentation to reflect this information. 

---

Senior Technical Writer
- Xceed Software

In three words I can sum up everything I've learned about life: it goes on.

Does this mean there is no way to do custom sorting when using a virtualized datagrid?

Hi John,

Unfortunately, custom sorting in a virtualized DataGrid is not currently supported.

 

---

** Quick Tip: Clients with an active support subscription should be sending their questions by email if they wish to benefit from the faster response time. Thanks!


Diane Lafontaine
Technical Support
Xceed Software Inc.