How to select all TreeView?

[lostluna1]

Anyway, when I set IsSelected=true; I can only choose the last one

[lostluna1]

@ghost1372 Do you have any good ideas? Looking forward to your reply

[ghost1372]

Do you mean you want to select all treeview items?
I think you should enable multiselect.
SelectionMode="Multiple"

[lostluna1]

I mean use code-behind to select all in TreeViewItem, not xaml "SelectionMode="Multiple""

[lostluna1]

My basic purpose is to bind the SelectedItem of the TreeViewItem according to the data in the vm, but since it is read-only, I cannot do so. I can only think of setting IsSelected of the TreeViewItem

[castorix]

When I do this in a test TreeView (tv1), it selects all items :

            tv1.SelectedItems.Clear();
            foreach (var rootNode in tv1.RootNodes)
            {
                tv1.SelectedItems.Add(rootNode);
            }

[lostluna1]

Your answer is perfectly, in china, about xaml info is so poor, very thanks your reply!!