textbox Empty validation
<p>I'm trying to validate a text box in a form to not having empty string if the user didn't entered anything in the text box, so if the text box was empty, the user has to enter a value ,and my code was like this, but it is not working</p>

<pre><code>  public int TextBox_Validation(string sender)
  {


      try
      {

          if (string.IsNullOrEmpty(sender))
          {
              MessageBox.Show("Please enter a value");
          }

      }
      catch
      {
          int num = int.Parse(sender);
          return 0;

      }
      return 0;
  }
</code></pre>
