Find controls being rendered in master page at runtime
<p>I have a master page which has a number of controls on it both from the content page and the master page itself. All these controls extend System.Web.UI.UserControl and some implement an interface called IControlInjector.</p>

<p>When the master page loads, is there any way I can check in the master page what controls are being loaded in the control tree and find all those that implement the IControlInjector interface? </p>
