6 posts, 0 answers
  1. Jim
    Jim avatar
    1 posts
    Member since:
    Jun 2009

    Posted 24 Jun 2009 Link to this post

    I am placing a RadExpander on a WPF window and set the IsExapnded property to False so when the window is loaded it (the expander) should display closed initially.

    I'm using a MVVM pattern so I initially thought that something was wrong with the binding, but after explicitly setting the IsExpanded="False" on the RadExpander control in the xaml I recieved the same result with the window opening with the expander open instead of closed.  I even went as far as coding in the code behind of the window loaded event handler to set the IsExpanded = False.  This didn't work either.

    The odd thing is the toggle thinks the expander is closed, but the content area is open.  so you have to toggle open and then closed and the functionality of the control starts to work.

    Here is the code:



    telerik:RadExpander x:Name="ValidationExpander" BorderBrush="#888888" BorderThickness="1" Background="#EEEEEE"          
    ="False" MinWidth="500" Canvas.Bottom="0" ExpandDirection="Up" Canvas.Left="0">








              <TextBlock x:Name="expanderCaption" Foreground="#000000" Visibility="Visible" />












                  <local:MessageBoxControl DataContext="{Binding MessageBoxViewModel, UpdateSourceTrigger=PropertyChanged}"











  2. Ivan
    Ivan avatar
    519 posts

    Posted 25 Jun 2009 Link to this post

    Hi Jim,

    Thank you for your interest in the RadExpander control.

    We confirm this is an issue with the WPF version of the RadExpander in our last release (2009-Q1)  and in order to workaround it you should toggle the IsExpanded to true and then to false.

    This issue is already addressed and the fix will be available in the upcoming Q2 release.

    Because of reporting the issue and sharing the workaround we updated your Telerik points.

    Best wishes,
    the Telerik team

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  3. AJ
    AJ avatar
    8 posts
    Member since:
    Oct 2010

    Posted 09 Nov 2010 Link to this post

    Has this been fixed yet. I am having the same issue on a project I am working on
     and I have the latest release.

  4. Viktor Tsvetkov
    Viktor Tsvetkov avatar
    382 posts

    Posted 10 Nov 2010 Link to this post

    Hi Arie,

    I cannot get such behavior. Could you please examine the attached sample project and if you have further questions do not hesitate to ask?

    All the best,
    Viktor Tsvetkov
    the Telerik team
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  5. Alex
    Alex avatar
    7 posts
    Member since:
    Jul 2015

    Posted 12 Dec 2016 Link to this post


    We are using RadExpander in our application and IsExpanded property is set to true in XAML. We are trying to capture AcutalHeight of the RadExpander on the load of RadGridView that's part of the RadExpander.

    The AcutalHeight is coming as 0 which is causing error.

    Can you please tell me why?

    Thanks and regards,


  6. Milena
    Milena avatar
    227 posts

    Posted 15 Dec 2016 Link to this post

    Hello Alex,

    I tried to reproduce the described  behavior locally but to no avail.

    Could you please elaborate a bit more on your scenario and give us more details about the structure of your application (the part where the RadExpander is) - where it is hosted, you said "on the load of RadGridView that's part of the RadExpander." - does this mean that there is a RadGridView inside the expander content? Because I tried this approach and on my side it works as expected. It would be great if you can send us an isolated project (or a code-snippet) so that we can test it locally and further investigate the reason behind this behavior.

    Thank you in advance for your cooperation.

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