title: WPF TreeView - Force SelectedEvent on Item that is already selected
body: <p>Summarized Question:<br>
  In the WPF TreeView, how can I force the selected event on an item that is currently the selected item?</p>
  
  <p>Detailed Info:<br>
  I am trying to add functionality to my WPF TreeView by adding multiselect using shift(for a range) and control(for toggling selection of an item). I've implemented my own SelectedItems collection since the TreeView only has a selected item. I still use the SelectedItem of the TreeView so that it does not break keyboard functionality, however I do overwrite the existing ItemContainerStyle so that even though an item is selected, it does not give the appearance that it is selected. I wouldn't have needed to do this however, I needed to only highlight the background of the textblock of my selected treeview items, rather than the entire width of the item, so I handle the foreground and background color changes on my own.</p>