title: GridView Conditional Button Visibility
body: <p>I have this itemtemplate for a gridview column that is pulling data from a SQL database. My Question is how would I perform a check to see if my field ActivityFile has a value (which means a file is in the db) and then display the LinkButton at which point I generate code to download the file (already done and works).</p>
  
  <pre><code>                &lt;ItemTemplate&gt;
                      &lt;asp:LinkButton ID="DownloadFileBtn" runat="server" visible="false"&gt;Download File&lt;/asp:LinkButton&gt;
                      &lt;br /&gt;
                     &lt;a href="&lt;%# Eval("ActivityLink") %&gt;"&gt;&lt;asp:Label ID="Label4" runat="server" Text='&lt;%# Bind("ActivityLink") %&gt;'&gt;&lt;/asp:Label&gt;&lt;/a&gt;
                  &lt;/ItemTemplate&gt;
  </code></pre>