Problem releasing object using "removeFromSuperView" iPhone.

Question

Hi

I have this concrete problem, but if You find my initial design idea crazy and have a better suggestion, please let me know:)

I have a UIView that acts as a container/background for adding other views. The important thing is that only one view is present at a time. So before doing any adding of views I do this:

        for(UIView *v in [self.currentView subviews]) {

        [v removeFromSuperview];
    }

self.currentView is the view I add my subviews to.

After this I add a new UIView in this manner:

        UIView *tempView;

    switch (self.currentIndex) {
        case 1:
            tempView = [[AView alloc] initWithFrame:frame];
            [self.currentView addSubview:tempView];
            [tempView release];
            break;
        case 2:
            tempView = [[AView alloc] initWithFrame:frame];
            [self.currentView addSubview:tempView];
            [tempView release];
            break;
        default:
            break;
    }

This way I remove all views, since I release the tempView straight after I add it to the self.currentView I end up with a retain count of one on the the UIView currently living in the currentView.

This all seems fine, but as I look at it with Instruments I can see that each time I run the above code a new AView object is allocated and the old one keeps hanging around with a retain count of 1, either I am missing some obvious retain action being performed on my object or else the "removeFromSuperView" does not call "release" on my view.

In real life my objects are not of type AView, but of many different types, but this way I can test if there is always only one AView instance allocated.

As I can read from the documentation "removeFromSuperView" should call "release" on the view so I am a bit confused as to why my Views are not deallocated.

Again, maybe I am going about this the wrong way and suggestions are really welcome. The setup is that there is a number of button at the bottom of the screen and when the user clicks on the view changes.

Thanks for any help or pointers given:)

Answer 1

You are iterating a collection and simultaneously changing it

Try

    while ([self.currentView subviews].count>0) {

    [[[self.currentView subviews] objectAtIndex:0] removeFromSuperView];
}

instead.

Answer 2

you could try the "bringSubviewToFront" and "sendSubviewToBack" functions instead of creating a new UIView everytime. That ways, you won't be creating uiviews for every action and therefore be less pressing on the memory consumption of your application.