title: Exclude non printable characters except new line
body: <p>I've an issue like this:
  <a href="https://stackoverflow.com/questions/1999566/string-filter-detect-non-ascii-signs">string filter: detect non-ASCII signs in C#</a> 
  but I should exclude all no-printable characters in a string <strong>except new line</strong> chars (\n).</p>
  
  <p>Starting from Regex option:</p>
  
  <pre><code>foo = System.Text.RegularExpressions.Regex.Replace(foo, @"[^\u0020-\u007E]+", string.Empty);
  </code></pre>
  
  <p>I've modified it in this way:</p>
  
  <pre><code>foo = System.Text.RegularExpressions.Regex.Replace(foo, @"[\u0000-\u0009\u000B-\u000C\u000E-\u0019\u007F]+", string.Empty);
  </code></pre>
  
  <p>This seems to work correctly, but could you suggest a less verbose solution?
  Thanks in advance</p>