Poor performance with controls?

[Jason]

I was previously used the free listpicker and autocomplete box from the silverlight toolkit and recently switched to telerik controls. I'm dealing with large databases and just started doing some performance testing on my older WP7 device and have an issue when I call a new page the UI would block for several seconds, 4+. I tried many things with background workers, etc, assuming it was the database but realize it's the telerik controls. Made a new project with a single button, calling another page with a autocomplete box and several  list pickers and I see the same thing, no code, just UI -  slow loading with UI blocked. The silverlight toolkit controls I was using previously had no such issue and would display almost immediately on page load. Am I missing something or are the controls just better optimized for newer hardware now? On my WP8 test device I don't really notice it.

[Jason]

Update ... I noticed when I returned to the page the speed was better or went to another page with the controls first, so I placed a hidden listpicker/autocomplete box on my main page which had no telerik controls before and cuts the load time down by almost half, guess it does some work the first time they're used and then is cached for future use?

[Kiril Stanoev]

Hello Jason,

Thank you for contacting us.
We haven't done any performance optimizations for the new platform (WP8). The changes between the WP7 and WP8 ListPickers are almost none so I assume the platform simply behaves better.
We'll try and reproduce the performance issue  using your approach and we'll see if the situation can be improved. We'll do this first thing next week as we're working this week with limited capacity due to national holidays. We'll let you know our findings. Sorry for the inconvenience caused.

Greetings,
Kiril Stanoev
the Telerik team

[Benjamin]

Is there anything to do about the first time?

[Todor]

Hello Benjamin,

Thank you for writing. 

The initial delay is caused by the parsing of the styles for the controls that are included the relevant assemblies. For example, when you use RadDataBoundListBox the styles of the controls in the Primitives assembly are parsed and when you use RadCalendar the styles of the controls in the Input assembly are parsed. You can use Jason's approach and add a control to the first page of your application. This way the loading time will be added to the app loading and will be less noticable. 
 
Regards,
Todor
Telerik