title: Need to update a window when another window is closed. Need to instantiate the closed window again
body: <p>I want to update my <code>MainWindow</code> by closing another window called <code>newProjectWindow</code>. I have an <code>Eventhandler</code> that updates my <code>Mainwindow</code> when the <code>newProjectWindow</code> is closed but I need the <code>newProjectWindow</code> again. But if I try to <code>NewProjectWindow.ShowDialog();</code> I get an error.</p>
  
  <p>Is there a possibility where I can somehow "reuse" the Window.</p>