How to Convert an ASP.NET Control to String

Problem
Need to generate an HTML string from an ASP.NET web control created in code-behind without rendering it on the web page.

Solution
Use the control's RenderControl() method with a StringWriter to generate the HTML.

  
// Code sample of a utility method to convert a control to an HTML string  
public static string RenderControlToString(Control control)
{
       string renderedControl = null;
       if (control != null)
       {
              using (StringWriter tempStringWriter = new StringWriter())
              {
                     using (HtmlTextWriter tempHtmlTextWriter = new HtmlTextWriter(tempStringWriter))
                     {
                           control.RenderControl(tempHtmlTextWriter);
                           renderedControl = tempStringWriter.ToString();
                           tempHtmlTextWriter.Close();
                     }
                     tempStringWriter.Close();
              }
       }
       return renderedControl;
}
 
// Test Utility Method
private void TestRenderControlToString()
{
       HyperLink testHyperLink = new HyperLink();
       testHyperLink.NavigateUrl = "/MyWebFolder/Default.aspx";
       testHyperLink.Text = "Hyper Link Value";
       testHyperLink.Target = "_blank";
       string renderedControl = Utility.RenderControlToString(testHyperLink);
       Response.Write(Server.HtmlEncode(renderedControl));
       Response.Write(renderedControl);
}

References
"Control.RenderControl Method (System.Web.UI)." MSDN: Microsoft Development, MSDN Subscriptions, Resources, and More. 27 Mar. 2009
http://msdn.microsoft.com/en-us/library/system.web.ui.control.rendercontrol(VS.80).aspx.

"StringWriter Class (System.IO)." MSDN: Microsoft Development, MSDN Subscriptions, Resources, and More. 27 Mar. 2009
http://msdn.microsoft.com/en-us/library/system.io.stringwriter(VS.80).aspx.