Is there a way to select manually a node in virtualizing TreeView and then bring it into view?
The data model I'm using with my TreeView is implemented based on the VM-M-V model. Each TreeViewItem's IsSelected property is binded to a corresponing property in ViewModel. I've also created a listener for TreeView's ItemSelected event where I call BringIntoView() for the selected TreeViewItem.
The problem with this approach seems to be that the ItemSelected event won't be raised until the actual TreeViewItem is created. So with the virtualization enabled node selection won't do anything until the TreeView is scrolled enough and then it jumps "magically" to the selected node when the event is finally raised.
I'd really like to use virtualization because I have thousands of nodes in my tree and I've already seen quite impressive performance improvements when the virtualization has been enabled.
Best Answer
The link Estifanos Kidane gave is broken. He probably meant the "Changing selection in a virtualized TreeView" MSDN sample. however, this sample shows how to select a node in a tree, but using code-behind and not MVVM and binding, so it also doesn't handle the missing SelectedItemChanged event when the bound SelectedItem is changed.
The only solution I can think of is to break the MVVM pattern, and when the ViewModel property that is bound to SelectedItem property changes, get the View and call a code-behind method (similar to the MSDN sample) that makes sure the new value is actually selected in the tree.
Here is the code I wrote to handle it. Suppose your data items are of type
Node
which has aParent
property:I wrote the following behavior class:
With this class, you can write XAML like the following: