Expand all root items

[hwsoderlund]

Hi, I need to make sure that all root nodes are expanded on initial load. With the CTP version of RadTreeListView (based on RadTreeView), I used the following:

void HierarchyTree_ItemPrepared(object sender, RadTreeViewItemPreparedEventArgs e)
{
    RadTreeViewItem item = e.PreparedItem;

    //Root items should be expanded on initial load
    if (item.IsRootItem)
        item.IsExpanded = true;
}

What is the simplest equivalent in the current version of RadTreeListView?

/Henrik

[Yavor Georgiev]

Hi hwsoderlund,

 You can handle the DataLoaded event of RadTreeListView like so:

void treeListView_DataLoaded(object sender, EventArgs e)
{
    var source = this.treeListView.ItemsSource as ICollection;
    if (this.treeListView.Items.Count == source.Count)
    {
        foreach (var item in source)
        {
            this.treeListView.ExpandHierarchyItem(item);
        }
    }
    else if (this.treeListView.Items.Count > source.Count)
    {
        this.treeListView.DataLoaded -= this.treeListView_DataLoaded;
    }
}

All the best,
Yavor Georgiev
the Telerik team

[Francois Lamy]

When I try to call ExpandHeirarchyItem in response to the DataLoaded event, I get an error 'Value does not fall in expected range', seemingly because there are no items in the treeListView.Items collection yet.  Am I missing something?

[Yavor Georgiev]

Hi Thomas Whittaker,

 Could you please post some code snippets so that I can learn a bit more about your scenario? A sample project would be best, though. If you are willing to send us a sample application, please open a support ticket. Either way, I'll try to help you as quickly as possible.

Sincerely yours,
Yavor Georgiev
the Telerik team

[Francois Lamy]

I am not exactly sure what I was doing wrong.  When I went back later and put my ExpandHierarchyItem call in the RowLoaded event handler, it worked.  I haven't gone back to try the DataLoaded event handler because RowLoaded was what I wanted anyway.

[Ivano]

Hi

your example works fine but when I set RadTreeListView.ItemsSource again DataLoaded event is no more fired; how shuold I expand all roots any time I set ItemsSource?

Thanks

[Richard M]

Reattach the event before you set the item source