Sorting/Grouping data in WP7 based on user input using LongListSelector

1
votes

I’m working on an inventory display app (master/details) for Windows Phone 7 where the user has the ability to change the sorting. The source of the data is XML from the web, and depending on the sort chosen, the results are either a flat list (sorted by name, model number, etc.) or grouped by the selected attributes (color, size, etc.). I'll pre-determine whether the sort returns flat vs. group and it won't be user selectable.

I’m displaying the results in a WP7 pivot control and want/need the different sorts to appear in the same PivotItem (putting the sorts in different PivotItems isn’t really an option). The source for the list is an Observable Collection (actually at this point it’s a CollectionViewSource, but I’m not wedded to either). I’m using the MVVM Light framework.

I’ve played with LongListSelector from the Silverlight Toolkit and it looks like it does what I want. I've read a number of posts (starting with WP7 ListBox Grouping) and actually have it working for the flat list (no sort applied, just default as it is from the source). Now I’m trying to figure out the right way to use it.

My questions:

  • Is it possible to re-structure the way the data is displayed (flat/sorted vs. grouped) without having to build/maintain multiple observable collections of the same info (one for each sort variant)?

  • If not, is the best method to save a local copy of the data locally on the phone and work from there? I expect I'd take a hit on complexity but pick up savings on perf/responsiveness.

  • To display the various results in the same PivotItem, should I create user controls with the appropriate formatting and swap them in to the pivot based on the chosen sort, or can I do it via dynamic ItemSource & ItemTemplate changes?

  • Is Observable Collection/CollectionViewSource the way to go here?

It’s entirely possible (even likely) the answers are staring me in the face, but I’m new to this stuff and I’ve hit data overload. I could really use some guidance.

Thanks, Rich

1
windows-phone-7mvvm-lightsilverlight-toolkit

1 Answers

0
votes

Is it possible to re-structure the way the data is displayed (flat/sorted vs. grouped) without having to build/maintain multiple observable collections of the same info (one for each sort variant)?

I think what you could try is using LINQ to query your given collection, and use that query as the source for your LLS. I'm not sure on how the performance would be, but you can give it a try. Alternatively, IIRC the various *ViewSource collections have ways of changing the view of your data, so you can check those out.