Is there an easy way to collapse organization chart tree view? I am thinking to put a little +/- icon at the bottom of every node and allow user to expand and collapse the tree view (in my case, org chart) when user clicks on it.
Sure, just add a Button to your node that toggles the value of Node.IsExpandedTree.
You also need to update the appearance of the button.
And you also need to make the button not visible when it’s known that there are no tree children.
The Visual Tree and Incremental Tree samples demonstrate different ways of doing these tasks.