Comments on: Creating a highlighting text block for Silverlight 3, revisited

By: slyi

slyi — Sun, 25 Oct 2009 19:01:23 +0000

Thanks for this i created a syntax hightlighter based on this and delay sample control http://blogs.msdn.com/delay/archive/2008/06/19/text-from-a-slightly-different-perspective-verticaltextblock-control-sample-for-silverlight-2.aspx http://forums.silverlight.net/forums/t/138293.aspx

By: Håkan

Håkan — Thu, 22 Oct 2009 08:17:14 +0000

I too, have the same problem as Gerard and not only when scrolling.
Sometimes items that does not match the text is displayed in the list, but when moving down to it with the arrow key and select it, it will be something else.
So it seems that the filtered list is correct but it displays the wrong values in the DataTemplate that uses the HighligtingTextBox.
If I remove the highlighting from my DataTemplate it works fine.

By: Jamel

Jamel — Thu, 10 Sep 2009 19:43:45 +0000

I have a larger list that requires me to scroll when I do the data bound to the HighlightTextBlock is out of sync with the data in the regular textblock. I tried Gerards suggestion of changing the class to extend form ContentControl and instantiating the TextBlock and add it to Content but this did not work. Any suggestions would be greatful

By: Gerard

Gerard — Mon, 31 Aug 2009 18:23:41 +0000

I modified the class to extend ContentControl instead of Control and modified the constructor to instantiate the TextBlock and add it to the Content.

That corrected the issue. Robby Ingebretsen’s TextBloc blog helped.

http://blog.nerdplusart.com/archives/texttrimming-textblock-for-silverlight

By: Gerard

Gerard — Mon, 31 Aug 2009 15:41:58 +0000

Simple test to reproduce the HighlightingTextBlock paint/draw issue. In a ListBox, add items bound to entities with a DataTemplate. In the DataTemplate bind a TextBlock and a HighlightingTextBlock to the same entity field. Make sure there are enough entities to scroll. Drag the scroll bar up and down fast. Notice how the TextBlock and the HighlightingTextBlock display different values.

Any helpful insight would be appreciated.

By: Gerard

Gerard — Thu, 27 Aug 2009 21:31:05 +0000

When I drag the AutoCompleteBox scrollbar up and down, the HighlightingTextBlock in the DataTemplate continues to change to other entities in the list. The TextBlock is always bound to the correct entity. The HighlightingTextBlock seems to do this as it redraws. The initial, visible portion of the list, before scrolling, matches the entities. No matter how I scroll, the HighlightingTextBox starts to display text from other entities in the list.

By: Jeff Wilcox

Jeff Wilcox — Thu, 27 Aug 2009 20:10:13 +0000

@Gerard,
interesting – Silverlight only has one UI thread. Any more info on the issue you are seeing?

By: Gerard

Gerard — Thu, 27 Aug 2009 20:00:27 +0000

Looks like there may be a problem with threading concurrency at private static void OnTextPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)

My AutoCompleteBox has a DataTemplate with a stackpanel holding a TextBlock and HighlightingTextBlock both bound to the same field of my entity. The TextBlock is always precisely correct as I can see and I arrow throught the results. The HighlightingTextBlock begins show text from later fields that do not accurately represent the current entity.

By: Jeff Wilcox

Jeff Wilcox — Wed, 26 Aug 2009 23:08:04 +0000

@Morten,
Definitely. This control was originally for a “proof-of-concept” implementation – it’s just back from the dead for this post

By: Morten

Morten — Wed, 26 Aug 2009 22:45:15 +0000

Wouldn’t it make more sense to make this a behavior you attach to the textblock instead? It would make the code simpler, and you can just throw it on existing textblocks instead of having to change them out with other controls. You could also make it a TargetedTriggerAction and use the textchanged event to trigger the action. This would make it more flexible on what triggers the highlight (ie. highlight on mouseenter on another UIElement etc)