Root node expand problem

[Radu]

Hi everyone. I have problems on expanding the root node of the treeview at start. I do not use data binding and I have about 4 hierarhical levels. In code at runtime I call the ExpandAll() for the level 0 nodes but they do not expand. If I expand the level 0 nodes afterwards in the UI I can see that all other levels below are expanded.

[Tihomir Petkov]

Hello Radu,

The ExpandAll method works after the UI elements of the treeview have been generated and you are probably calling the method before that has happened. In case you declare your treeview items in XAML, you can simply set the IsExpanded property of the root item to true. Alternatively, you can listen for RadTreeView's ItemPrepared event and programatically set the prepared item's IsExpanded property to true. In the second case you will only have to do this the first time the event occurs, because the event is fired for every item that is being rendered and after you expand the root item the event will be fired for every child item.

Let me know if this helps and please do not hesitate to ask if you have further questions.

Greetings,
Tihomir Petkov
the Telerik team

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[Radu]

Thanks a lot. It worked

[Maria Im]

It's a bit like Radu's problem but mine is different. I have the treevoew and Load on demand for each items like s

1. Treatments
        2.VisitDate
                3.Documents
                3.Images
                3.FreeHandNotes
1.Treatments
       2.VisitDate
       2.VisitDate
            3.Documents
            3.Images
            3.FreehandNotes ..etc...

As of Now, the treatments load fine. then if you click on Treatment it activates the Load on Demand and displays visit date and if you click VisitDate it will display {documents, images and freehand notes). Now I want to load it initially with the treatment expanded, showing only the VisitDate like so:

1. Treatment 1
        2.VisitDate
1.Treatment 2
        2.VisitDate
1.Treatment 3
        2.VisitDate

Under the item prepared event, I put the code so that the curreent item prepared IsExpanded property is set to True. But when it displays on the screen, only the last treatment is expanded while the first 2 treatments asre still trying to load. Please help.

[Kiril Stanoev]

Hi Maria,

I've prepared a sample project trying to mimic your scenario. I did not find any problems using the LoadOnDemand and expanding features. Could you please have a look at it and let me know if I am missing something. I'd be glad to further assist you.

Best wishes,
Kiril Stanoev
the Telerik team

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[Maria Im]

Thanks. That answered my question.

[farhan iqbal]

I got a similar problem (with minor difference).
I don't have any specific format of data, i.e. I had to load any XML file in my treeview, so I've to do this on runtime. What I do is, I manually create RadTreeViewItem and add it in the treeview in Window_Loaded event. A sample tree view could be:
GrandFather
          Father1
          Father2
                Child1
                Child2
          Father3
                Child1

My problem is, if I had to expand a particular item (e.g., Father3 or GrandFather) RadTreeViewItem.IsExpanded = true not works for me, (either on window_Loaded or ItemPrepared)

[farhan iqbal]

sorry for posting the already posted problem, this will solve the issue:
http://www.telerik.com/community/forums/wpf/treeview/item-selection-problem.aspx