You SHOULD NOT be adding views to a UIAlertView this is a one fast track ticket to getting your app rejected from the App Store, check out the section mark as Subclassing Notes from the Apple UIAlertView Documentation
Subclassing Notes
The UIAlertView class is intended to be used as-is and does not support subclassing. The view hierarchy for this class is private and must not be modified.
In iOS7 Apple basically re-enforced the above by making it so addSubview: actually did nothing, it is there still though because UIAlertView is a subclass of UIView and UIView can still respond to this method. Many have however written custom AlertViews check out iOS Custom AlertView for example