Render data offscreen in UIView

How would I go about drawing a view offscreen in or开发者_StackOverflow社区der to perform some calculation before the view's draw is actually done? Can this be done by drawing to a temporary layer?

I am not getting your exact problem... But you can use

-(void)viewWillAppear:(BOOL)animated

this method will be called every time before your view will appear on the screen... you can do the calculation and make some changes here before view appear on the screen...