Silverlight for Windows Phone Performance team blog - All Comments

re: Silverlight for Windows Phone 7: ListBox Scroll Performance

onmyway133 — Sat, 08 Dec 2012 11:27:27 GMT

"Add items to the UI thread in batches every some miliseconds (example add 2 items every 20ms)". Does switching between thread many times like this affect performance ?

re: Silverlight for Windows Phone 7: ListBox Scroll Performance

onmyway133 — Tue, 13 Nov 2012 13:13:00 GMT

I know that the Windows Phone 7 ListBox use VirtualizingStackPanel by default to optimize memory.

However, when I add more items to the view model, the listbox doesnot show those new items. I must scroll up, then down to see them.

My view model does implement IList

Many articles around have this problem

How to fix this ?

re: Silverlight for Windows Phone 7: ListBox Scroll Performance

Vishal Gandhi — Tue, 06 Nov 2012 06:34:16 GMT

David Anson's DeferredLoadListBox does not work for variable height items. Needs correction.

re: Windows Phone Mango change, Listbox: How to detect compression(end of scroll) states ?

Zaxxonal — Mon, 03 Sep 2012 14:08:01 GMT

Thanks for this excellent post. I converted the code to vb for use in my project, and posted the adapted code.

ericsgems.wordpress.com/.../daily-gem-vb-silverlight-wp7-5-infinite-scrolling-lists

re: Windows Phone Mango change, Listbox: How to detect compression(end of scroll) states ?

Casper — Thu, 19 Jul 2012 10:18:08 GMT

I've got the same problem as punit. I can't get it to work when using a ScrollViewer element, instead of a scrollable ListBox.

Any idea on how to fix that?

re: Silverlight for Windows Phone 7: ListBox Scroll Performance

webaloman — Tue, 03 Jul 2012 09:28:41 GMT

Any possibility to use vitrualization trough IList when I use observable collection for my ListBox?

Or just use the batch approach mentioned above (adding 2 items every 20 ms to the UI thread)

re: Windows Phone Mango change, Listbox: How to detect compression(end of scroll) states ?

punit — Tue, 29 May 2012 01:11:16 GMT

I'm not using a ListBox, but just a ScrollViewer with a number of elements in it. When I pass the ScrollViewer to this call:

FrameworkElement element = VisualTreeHelper.GetChild(sv, 0) asFrameworkElement;

I get an "ArgumentOutOfRangeException": {"Specified argument was out of the range of valid values.\r\nParameter name: childIndex"}

re: Windows Phone Mango change, Listbox: How to detect compression(end of scroll) states ?

Jeremie — Mon, 19 Mar 2012 00:50:37 GMT

Is that possible to change Compression's value?

I mean the way i hit the top/end of my listBox (heavy/light).

re: Off-thread decoding of images on Mango, how it impacts your application ?

Patrick Long — Fri, 18 Nov 2011 16:31:47 GMT

I am also having the Invalid Xaml issue that Adi811 is reporting

re: Silverlight for Windows Phone 7: ListBox Scroll Performance

Ernest — Wed, 28 Sep 2011 10:20:37 GMT

I have listbox binded content (observable collection, which have images too)

On async request i populate collection by clearing and adding new content, at that time flicker occurs and seems it involved whole pivot page, on which i have listbox.