title: Delay the presentation of UIAlertView until its associated viewController is displayed
body: <p>I have a download running in background. It shows an UIAlertView under some fail condition.</p>
  
  <p>When this alert happens, the application can be in any of the views it shows to the user, but only should be visible in one of them.</p>
  
  <p>Can I delay the presentation of the UIAlertView to the moment the viewController it is associated with is displayed to the user (it's viewDidAppear method is invoked)?</p>