title: Convert a Unicode string to an escaped ASCII string
body: <p>How can I convert this string: </p>
  
  <pre class="lang-none prettyprint-override"><code>This string contains the Unicode character Pi(π)
  </code></pre>
  
  <p>into an escaped ASCII string: </p>
  
  <pre class="lang-none prettyprint-override"><code>This string contains the Unicode character Pi(\u03a0)
  </code></pre>
  
  <p>and <em>vice versa</em>? </p>
  
  <p>The current Encoding available in C# converts the π character to "?". I need to preserve that character.</p>