title: C# format a double with ToString, and dispay zero value
body: <p>I'm trying to find the best way to display a double in C# as follows:</p>
  
  <ul>
  <li>7.345 should display as "73"</li>
  <li>100.0 should display as "100"</li>
  <li>0.234 shoud display as "02"</li>
  </ul>
  
  <p>The input is a value between 0.00 and 10.00. I need to convert it to a filename. E.g. in case of a value of 5.4234, I should display "<code>img54.jpg</code>".</p>
  
  <p>The problem is that I can't figure out how to display zero values in <code>ToString()</code> of doubles.</p>
  
  <p>I tried this:</p>
  
  <ul>
  <li><code>(10 * 7.345).ToString("##.")</code> => correct</li>
  <li><code>(10 * 10.00).ToString("##.")</code> => correct</li>
  <li><code>(10 * 0.000).ToString("##.")</code> => FAIL, doesn't display anything.</li>
  <li><code>(10 * 0.000).ToString("D2")</code> => FAIL, D is not allowed in doubles</li>
  </ul>
  
  <p>I can of course do some sophisticated string building, but if it's possible to use <code>ToString</code>, that would be much better of course.</p>
  
  <p>Anyone an idea?</p>