Disappear when using inside RadDocumentPane Docking Tabs

[Andrew Diamon]

My app uses Docking to create a MDI interface.  I can load the HTMLPlaceHolder in a tab the FIRST time just fine.  When the tab is closed and then recreated / reopened the PlaceHolder appears then immediately disappears.  It's almost like it's reusing the same PlaceHolder.  The PlaceHolder exists and I can access it in code, but it is invisible.  I'm thinking it is hidden behind the Docking, which is taking up the whole window?

Also, this may be related to the Docking never actually disposing of the closed tab from memory.  Has this been resolved?

http://www.telerik.com/community/forums/silverlight/docking/raddocumentpane-closed-or-hidden.aspx 

[Zarko]

Hi Andrew,
Unfortunately I wasn't able to reproduce the issue but I have a couple of suggestions:
- you can set the RadPaneGroup.IsContentPreserved property to True. However, please keep in mind that at the moment this property doesn't work well when the tabs display an HtmlPlaceholder with KeepContentInMemory=True. This is why you can try setting only the IsContentPreserved property to True.
- you can try to set a static size to your HTMLPlaceHolder (something like Width = 300, Height = 300) because in some cases (depending on its parent) it's not able to render itself properly.
If this doesn't help you I'd like to ask you for some code snippets so that we could reproduce the issue.
We're looking forward to hearing from you.

All the best,
Zarko
the Telerik team

[Yvan]

Hi Zarko,

I have the same problem as Andrew.
I tried with the latest version of telerik telerik RadControl for (2012.2.0924). This seems to be new since Q1 2012 SP1 version did not have this behavior.

 I sent you an Silverlight 5 example with the support ticket 612278.
 
Thanks

Yvan

[Zarko]

Hello Yvan,
I'll copy/paste my answer from the support thread so that anyone with similar problem may read it:
"Thank you for the feedback and the sample project! It seems that there's a bug in the HtmlPlaceholder and I've logged it in our PITS under the name "The placeholder disappears if it's in a RadPane and you close another RadPane" . The item should be ready for tracking and voting tomorrow the latest.
As for now I can give you a possible workaround (it's not very nice but it works) - your HtmlPlaceholderControl should implement INotifyLayoutChange and you should call its LayoutChangeEnded event on RadPane close.
I've changed your project so could you please examine it and if you have further questions feel free to ask."

Regards,
Zarko
the Telerik team