Update Panel error: Control with the ID “xxx” could not be found in the UpdatePanel

Question

I have a composite drop down calendar user control that consists of a textbox and and calendar image and a validation control. I expose a property called \"TextBox\" on the

Answer 1

For an html control runat server inside of an update panel you need to dereference the update panel to get a handle to the control on the server side:

using System.Web.UI.HtmlControls;

HtmlControl x = (HtmlControl)this.MyUpdatePanel.FindControl("MyHtmlControl");