I am implementing a listview, and a button next to it. I have to be able that when i select multiple items in a listview, and then click on a button, then the selected items
It's kind of tricky to do this Mutliple Selection in MVVM, because the SelectedItems property isn't a Dependency Property. However, there are some tricks you can use. I found this triology of blog posts that describe the matter in some details and provide some useful solutions.
Hope this helps