创建类似于UIAlertView演示的Pop动画

I would like to present a view in the same manner as that of UIAlertView - a pop/spring. Unfortunately subclassing UIAlertView is not an option for the view I need to present. I have written some code, but I can't seem to get it as realistic as I would like. I would appreciate any suggestions for greater realism or a link if anything similar has been done (I could not find anything on Google). Thank you.I would like to present a view in the same mann