Release memory in iPhone SDK

Question

Hi,
1. I want to release previous memory before I redraw the screen. Is this the right way to do it using iPhone SDK?
[self.securityCodeView release];
self.securityCodeView = [[SecurityCodeView alloc] initWithFrame:Frame];
[self addSubview:securityCodeView];
[\b]
2. How do I refresh the screen without having to ALLOC memeory again? For example, I draw the screen ([self addSubview:securityCodeView]) and after one second, the screen needs to be redrawn (what statement to use?).
3. How do you retain some UIViews without redrawing since they don't need to be redrawn again (what statement to use)? For example, backgroundView needs not to be redrawn.
Thank you.

Answer 1

I would suggest you read the docs on Memory Management on Obj-C. Basically anything you allocate explicitly will remain allocated (with a ref count of 1) until you explicitly do a release:
[myView release];
When you add a view to another view's subview, that view's ref count is incremented. So you can safely release the added view and yet use the references to the object throughout the code (as long as the parent view is not released/deallocated).