Navigation Controller Stack

[ELA]

Hi,

I've got into a situation where I need expert help.

I'm trying to create an Flash Card Application, where user can swipe through group of image (audio + image) cards. I've used the Navigation Controller to manage the view controllers.

The problem, when the user pushes to the 10 or 11th view controller, my application reaches around 9 MB of memory. For example, if my navigation controller stack has the following view controllers in it;
- RootViewController
- ViewController1
- Viewcontroller2
- ViewController3
- Viewcontroller4
- ViewController5
- Viewcontroller6
- ViewController7
- TopViewController

If my navigation controller stack has 8 view controllers, excluding the root, I would like to nullify the view's (or some thing else, which would release the memory associated with that view controller) associated with the view controllers 1 - 5 (I still want to have these view controllers part of my navigation controller stack. Just want to release the view (which has an subview of UIImageView) associated with them.

Is there any way I can achieve that?

Also, when the user swipes back (navigating backwards, where I pop the top view controller) and reaches the above nullified view controllers, I want to reload the image and show it to the user.

I'm not sure whether I explained my requirement/issue properly. Please let me know if I didn't.

Thanks
Ela

[Tambourin]

normally you would release the hidden views, but I don't think this is possible for views belonging to a navigation controller.

you can write for each of your view controllers a releaseContent function where you release all the subviews/images of the view, but not the view itself.
similarly you write an allocContent function for each view.
then you call the releaseContent function when another view gets pushed on top and call the allocContent function when the view reappears.

[ELA]

Thanks Tambourin. I would try that way and let you know the results.

Thanks
Ela

Originally Posted by Tambourin

normally you would release the hidden views, but I don't think this is possible for views belonging to a navigation controller.

you can write for each of your view controllers a releaseContent function where you release all the subviews/images of the view, but not the view itself.
similarly you write an allocContent function for each view.
then you call the releaseContent function when another view gets pushed on top and call the allocContent function when the view reappears.