title: Textbox with Semi-Transparent Background
body: <p>Semi-Transparent background of the Textbox is needed, and the text content should be shown as normal.</p>
  
  <p><strong>Style</strong> or <strong>Brush</strong> which can store in the Resource dictionary is good.</p>
  
  <p>NOTE:</p>
  
  <ol>
  <li><p>My textBox is wrapped within a ContentControl.</p></li>
  <li><p>This similar question does not help. <a href="https://stackoverflow.com/questions/5557365/textbox-with-a-transparent-background">TextBox with a Transparent Background </a>.</p></li>
  </ol>