title: How to extract font size of content
body: <p>I've been working on making my own little text editor using a RichTextBox(MyRTB). I've made a Combobox to change the font of the selected text within the RichTextBox when the value changes using this code block:</p>
  
  <pre><code>private void CmbFont_SelectionChanged(object sender, SelectionChangedEventArgs e)
      {
          if (MyRTB != null)
          {                
              string fontsize = (((ComboBoxItem)CmbFont.SelectedItem).Content).ToString();
              MyRTB.Selection.ApplyPropertyValue(Run.FontSizeProperty, fontsize);
          }
      }
  </code></pre>
  
  <p>Now I'd like my Combobox value to change every time I select a string of text within the RichTextBox that has a different font size. Is this possible?</p>
  
  <p>Thanks</p>