I have a user control that injects a css file into the page header from its Page_Load event like this:
link2.Href = Page.ResolveUrl(
Page.Header.Controls.Add(link2);
This works fine on a stand alone aspx page.
When I try to add the control to a content page (that's using a MasterPage), I get the following error on the user controls Page.Header.Control.Add(link2) line:
The control collection cannot be modified during DataBind, Init, Load, PreRender or Unload phases.
Can anyone tell me how to get this to work in a Master/Content page context? The PreInit event won't work because it isn't accessible in a user control. And I need the user control to add the css file as the selection of css file to use needs to be a design time decision.