title: How do I format a double to a string and only show decimal digits when necessary?
body: <p>I have code like:</p>
  
  <pre><code>lblFranshizShowInvwNoskhehEdit.Text = string.Format("{0:n}",
      (double)(int.Parse(drDarman["FranshizDarsad"].ToString()) * 
          Convert.ToInt64(RadNumerictxtPayInvwNoskhehEdit.Text)) / 100);
  </code></pre>
  
  <p>But <code>{0:n0}</code> string format forces the label's text to not have decimal digits and <code>{0:n}</code> string format forces the label's text to have 2 decimal digits (default).</p>
  
  <p>In my scenario I just want decimal digits when necessary / without rounding them / how can I do that?</p>