private string RenderControl()
{
var sb = new System.Text.StringBuilder();
using (var stWriter = new System.IO.StringWriter(sb))
using (var htmlWriter = new HtmlTextWriter(stWriter))
{
var p = new Page();
var ctrl = (YourControl)p.LoadControl("~/controls/building blocks/YourControl.ascx");
ctrl.Visible = true;
// do your own init logic if needed
p.Controls.Add(ctrl);
ctrl.RenderControl(htmlWriter);
return sb.ToString();
}
}