title: How to bind WPF control text to boolean, and make decision about text in xaml
body: <p>I have a button control in a WPF application which is used for log-in purposes.  The button is dual purpose: when logged-out, it shall display the text "log in".  When logged-in, it shall display the text "log out".</p>
  
  <p>I could do this with databinding to an appropriate string property in the viewmodel.
  But it would be neater if I could simply databind to the "loggedIn" boolean (false for logged-out, true for logged-in) and then make the decision about what text to display on the button from within the view.</p>
  
  <p>Is this possible?</p>