Bea

I know it’s been a while, but great post all the same. I’ve managed to implement something of a solution to Silverlight’s lack of data virtualization. I’ve blogged about it here: http://kentb.blogspot.com/2010/07/virtual-paging-in-silverlight.html

Best,
Kent

I wrote a blog post that covers the scenario you describe – sorting with data virtualization.

Thanks,
Bea

I query a database table for information and the information is stored in a DataTable
object. There are about 100000 rows in the DataTable object. The information in the
DataTable will be to displayed in a listview. Each row in the DataTable object represents
an object that will be displayed in the listview. So in Bea’s download code when the Load
method is called startindex would reference a row position in the DataTable from which a
new VincentCustomer is created. Now the startindex to row position indexing is no problem
when no sorting is not involved. When sorting is involved I have to sort the whole
DataTable and now just section of the Virtual list as appears in the download code and
Vincent talks about. Am I missing a connection here? Since my DataTable creates the
VincentCustomers how do I sort a slice of the DataTable? The VirtualList never ever holds
all 100000 object that the DataTable object contains so in reality does this quick sorting
routine Vincent’s talk about actually work in reality?

If anyone has some source code that downloads information from a database and uses
Vincent’s data virtualization and has the quick sorting working could you post a link to
the source code so other can download it? All I can see is having to sort the how
DataTable using the default View of the DataTable since the VirtualList never contains all
1000 objects. If I am missing something could some post what I am missing?
steve_44@inbox.com is my email address if you would like to email a link to some source or email me some source code.

I haven’t yet heard of anyone who has implemented a data virtualization solution for Silverlight. If you find someone who has, please post it here, as I’m sure others would benefit from that knowledge.

Thanks,
Bea

Please take a look at my other blog post that combines advantages of both solutions.

Bea

Yes, it appears that the code was removed from Vincent’s server. I’ve uploaded his source code to my server, and added the link to the blog post. You can find it here.

Also, please keep in mind that I have another blog post that combines advantages of both solutions compared in this post.

Thanks,
Bea

The filtering, sorting and grouping built-in features in WPF need to access all items of the collection on the client side, which negates all the benefits of data virtualization. The only way to perform these operations together with data virtualization is to implement them yourself on the server side. I show in this post how to do that for filtering, and I have a post coming that shows the same thing for sorting. You could use those as inspiration to implement grouping (or maybe I’ll do that for a future post, if time permits).

Hope this helps.

Bea