I have implemented multi select on my tree view following the idea
I have gotten the selection working for both Shift select and Ctrl-Select.
The problem I have now is when I Ctrl-Click on to a selected item the item does not show as unselected until I ctrl-click on another item. When I click the selected
item I remove it from my selected list and set the IsSelected = false. I have added trace in the dependency property callback to make sure it really does get set to false and I have made sure I call the OnPropertyChanged(“IsSelected”) callback.
But it seems to be lacking ‘one behind’ all the time when I ctrl-click on already selected items.