Expand Nested Properties At Startup

[Andrew]

I've searched for this for a while.  Is there a way to expand/collapse nested properties via code-behind?  It would be nice to have all properties expanded by default in my program.

[Yoan]

Hello Andrew,

In order to achieve your goal, you can handle RadPropertyGrid's  Loaded event and execute the following code:

this.Dispatcher.BeginInvoke(new Action(() => { (sender as RadPropertyGrid).ChildrenOfType<RadToggleButton>().FirstOrDefault(b => b.Name == "PART_NestedPropertiesButton").IsChecked = true; }));

I believe that is what you are looking for.

All the best,
Yoan
the Telerik team

[Chris]

I did the way you suggested, it works but before the expanded field shows, I got a dispatcher exception dialog (please see the attachment).  Any idea?
Thanks.

[Ivan Ivanov]

Hi,

 You can try setting the IsExpanded property of PropertyDefinition on the occurrence of AutoGeneratingPropertyDefinition event. It is a relatively new property, which was introduced with Q2 2013.

Regards,
Ivan Ivanov
Telerik

[Chris]

Thanks, it works.

[Alexandru]

Hi!

I have a property grid, and it has NestedPropertiesVisibility="Visible". I want to have all the children expanded by default, and for this i have edited the grid's template, and changed the flatTemplate like this:
 <DataTemplate x:Key="flatTemplate">
            <ItemsControl ItemsSource="{Binding Converter={StaticResource FlatItemSourceConverter}}" Style="{StaticResource ItemsControlStyle}" IsTabStop="False">
                <ItemsControl.ItemTemplate>
                    <DataTemplate>
                        <telerik:PropertyGridField IsExpanded="True" Content="{Binding}" telerik:StyleManager.Theme="{StaticResource Theme}" Visibility="{Binding Visibility}"/>
                    </DataTemplate>
                </ItemsControl.ItemTemplate>
            </ItemsControl>
        </DataTemplate>

I have added the isExpanded property to true. However, the whole application crushes, and the only difference is the IsExpanded property. 

I have the sample project, but cannot upload it in this post. How can I do this?

Can you help please?

Regards,
Alex
       

[Dimitrina]

Hello Alex,

Indeed, it is just allowed to add screenshots with the forum posts. You can open a new support thread and attach the sample solution there. 

Regards,
Dimitrina
Telerik

 

 

[Alexandru]

How can I open a new support thread?
I get:
"Your license has expired or does not include dedicated support. Please visit Renewals and Upgrades or contact your license holder."

Anyway, I have renamed the archive as jpg, can you change please the extension back to zip, and extract tha project?

Regards,
Alex

[Alexandru]

Hi!

I didn't attach the telerik libraries, but i'm using v2014.3.1202.40

[Dimitrina]

Hello,

Thank you for providing a sample project. I was indeed able to reproduce the issue.

Is the change you refer to the only change you made when editing the template:

<DataTemplate x:Key="flatTemplate">
     <ItemsControl ItemsSource="{Binding Converter={StaticResource FlatItemSourceConverter}}" Style="{StaticResource ItemsControlStyle}" IsTabStop="False">
         <ItemsControl.ItemTemplate>
             <DataTemplate>
                 <telerik:PropertyGridField IsExpanded="True" Content="{Binding}" telerik:StyleManager.Theme="{StaticResource Theme}" Visibility="{Binding Visibility}"/>
             </DataTemplate>
         </ItemsControl.ItemTemplate>
     </ItemsControl>
</DataTemplate>

 
As it turns out once I commented the template of RadPropertyGrid as you have redefined it and I subscribed for the AutoGeneratingPropertyDefinition, setting the IsExpanded property of PropertyDefinition, it worked fine. Is it an option for you to use this approach instead? 

Regards,
Dimitrina
Telerik

 

 

[Alexandru]

Hi Dimitrina!

Thanks for your answer. I also used this approach, unsuccesfully.
The property grid I am having issues with contains collection editors, which I have also redefined to be able to costomize them. They also contain property grids, nested. I was able to use the event you mentioned to trigger a command instead, on all property grids, and the expand was working relatively fine, however:

1. the grids flicker 3-4 seconds when expanding all properties, on all levels
2. if the object binded to the primary grid is very complex (if it has a lot of children with lists of children with lists of children), these expansions will result in a strage exception, similar to the one mentioned above

I was hoping to be able to have all properties expanded by default. And I don't understand why setting this property, IsExpanded, to true, has such a strange behaviour. 

I also redefined the PropertyGridField, based on telerik xaml source code, until I reached the '+' toggle button, to eliminate any Visual effects, but still was not able to sort this out

Thanks,
Alex

[Dimitrina]

Hello,

As it turns out we can currently suggest using the approach with expanding the PropertyDefinitions when the AutoGeneratingPropertyDefinition event is raised.

Regards,
Dimitrina
Telerik

 

 

[Alexandru]

Hi!

Ok, but is the only solution? If yes I'm dissapointed because as I mentioned before, this doesn't work well on complex objects. I can provide an example if you require

Regards,
Alex

[Alexandru]

Hi!

Ok, but is this the only solution? If yes, I'm dissapointed, because as I've mentioned above, this doesn't work well on more complex objects. I can provide a sample if you require

Regards,
Alex

[Dimitrina]

Hi Alex,

I am afraid we cannot suggest another way to achieve your goal. Please excuse us for the inconvenience.

Regards,
Dimitrina
Telerik

 

 

[Alexandru]

Hi!

Ok, I understand, but please tell me if in future versions of the PropertyGrid Control will this be fixed or will remain the same

Regards,
Alex

[Dimitrina]

Hi,

I can also suggest you one alternative solution subscribing for the Loaded event of RadPropertyGrid.
For example:

private void grdPropr_Loaded(object sender, RoutedEventArgs e)
{
    grdPropr.PropertyDefinitions.SuspendNotifications();
    foreach (var item in grdPropr.PropertyDefinitions)
    {
        item.IsExpanded = true;
    }

    grdPropr.PropertyDefinitions.ResumeNotifications();
}

Please note you should additionally configure the control with:

RenderMode="Flat" 

as this is only supported in Flat mode.

Upon your request, I logged the suggestion as a Feature Request in our public Feedback Portal. You can vote for it and also follow its progress here:
Allow expanding nested properties at startup.

Regards,
Dimitrina
Telerik

 

 

[Alexandru]

Hi!

Thank you for your response, I managed to solve the problem by using RenderMode="Flat". This helps solving the exceptions which occured before.

Regards,
Alex