Why is IsChecked property nullable boolean in WPF CheckBox?

Question

Is there a case when IsChecked property on WPF CheckBox null ?

I guess that will answer my question from title of question.

Answer 1

If we want to bind a value from DB and if that value is null then we have to handle that also. A boolean DB value can be True, False or NULL. So the UI checkbox also must be handle the there states. That's why WPF CheckBox has three state.