title: Error after changing name of mainwindow
body: <p>I'm using WPF for the first time and I get an error like this:</p>
  
  <pre><code>Cannot locate resource 'mainwindow.xaml'
  </code></pre>
  
  <p>That is becuase I changed the name. Have I missed to change this is some other code? I'm not so familiar with this type of projekt, compared with Windows Form that I used before. Which file launch the application? I have been looking for one in the solution explorer. I guess it's perhaps there the error is?</p>