When creating an UIAlertView in code, the frame and bounds aren't calculated, yet. But even in the delegate method willPresentAlertView, there are still just zeros in the CGRects. Is there a way to determine an UIAlertView's size, or - as I only need its width - is the width of the view predetermined by iOS and the device?
In the comments you mention you want to add custom subviews to your alert. I wouldn't recommend this approach, but look at an alternative such as SDCAlertView (full disclosure: I wrote it).
In any case, the width of an alert is 270 points.