title: Converting empty string to Char
body: <p>My application executes a store procedure from a webpage parameters list I have field in table which is char type now I have to fill that value from a dropdownlist which could be empty or it may have value.</p>
  
  <p>I am taking that value as string </p>
  
  <pre><code>string productPreFix = Convert.tochar( drpProductIdFix.SelectedValue.ToString().Trim());
  </code></pre>
  
  <p>This throws me error how can I convert the value to char and it also handle null if dropdownlist is empty.</p>
  
  <p>thanks in advance for help </p>