WPF ListBoxItem selection problem

Question

I have a listbox where the items contain checkboxes:

Answer 1

To begin with, put the content outside the CheckBox:

After that, you will need to ensure that pressing space on a ListBoxItem results in the CheckBox being checked. There are a number of ways of doing this, including a simple event handler on the ListBoxItem. Or you could specify a handler for UIElement.KeyUp or whatever in your DataTemplate: