WPF TreeView with Multiple Selection

Question

Dear ladies and sirs.

Does anyone know of a good implementation of a WPF TreeView with multiple selection?

I am currently aware of one commercial implementation - http://www.telerik.com/products/wpf/treeview.aspx

My employer has no problem spending money on a commercial product, so I would like to know more of good commercial implementations.

Thanks.

Answer 1

I've written a blog post on how to implement this on the WPF tree view control,

Implementing Multi Select behavior on the WPF Tree View Control

Answer 2

Depending on the exact semantics you desire, the solution may be extremely simple:

If the root of your tree is anything but a TreeView -- for example if it is a plain ItemsControl -- all TreeViewItems in the tree will be independently selectatble so you basically get mulitiselect for free. So just use an ItemsControl instead of a TreeView for the root of your tree.

This solution has the benefit of being extraordinarily simple to implement. It differs from mattdlong's solution in that:

• His solution deselects all other items when an item is clicked, so you have to ctrl-click items to multiselect.
• With this solution a single click will select/deselect the item you clicked on, but there is no way to quickly select an item and simultaneously deselect all others.

Another difference is that keyboard navigation (arrow keys) in his solution deselects all items, whereas in this solution keyboard navigation does not deselect items.

You should choose between these solutions based on the semantics you prefer (single click to add item vs ctrl-click to add item, etc). If you want more advanced semantics, such as Shift-Click, etc, it is relatively to add.

Note that you can also custom style TreeViewItems using a ToggleButton or CheckBox anywhere in the ItemContainerTemplate that has Checked={Binding IsSelected}. This allows the user to select items by clicking on the ToggleButton or CheckBox.