Question

I am have an issue with my scrollview which holds multiple views. I think the problem is that subviews are being released. I have buttons in the subviews and when I click the buttons I get this error, [GraphDisplayViewController performSelector:withObject:withObject:]:

message sent to deallocated instance

. If there is only one subview then I can just use a property and this works, but since the number of subviews varies(one or more), it does not work and I don’t know how to solve this.

I currently load all the views at once in the beginning. I’m working on only loading one subview at a time and assigning the property to that view, but I’m not sure if that will work.

My layout is as follows, a parent view(DetailViewController) contains a scrollview, I add views(GraphDisplayViewController) to the scrollview, the subviews each load a view(GraphView).

Any help or advice would be greatly appreciated. If you need any more details please let me know. Thank you for your time.

Code sample of how I add the subviews,

DetailViewController

- (void)loadScrollViewWithPage:(int)page
{
if (page < 0) return;
if (page >= pageControl.numberOfPages) return;

subView = [viewControllers objectAtIndex:page];   
NSString *description;
NSString *packsize;
if ((NSNull *)subView == [NSNull null]) 
{
    subView = [[GraphDisplayViewController alloc] initWithNibName:@"GraphDisplayViewController" bundle:nil];
    [viewControllers replaceObjectAtIndex:page withObject:subView];
    subView = [[GraphDisplayViewController alloc] init];
    subView.molecule = moleculeName;
    subView.description = description;    
    subView.dataArray = moleculePrices;

}
else
{
    return;
}

// add the controller's view to the scroll view
if (nil == subView.view.superview) 
{
    CGRect frame = scrollView.frame;
    frame.origin.x = frame.size.width * page;
    frame.origin.y = 0;
    subView.view.frame = frame;
    [scrollView addSubview:subView.view];
} 
}

UPDATE
There was a mistake in the code, testing to see if that solves anything

subView = [[GraphDisplayViewController alloc] initWithNibName:@"GraphDisplayViewController" bundle:nil];
[viewControllers replaceObjectAtIndex:page withObject:subView];
subView = [[GraphDisplayViewController alloc] init]; <- Mistake

Answer 1

There was a simple error in my code, I init the view twice.

subView = [[GraphDisplayViewController alloc] initWithNibName:@"GraphDisplayViewController" bundle:nil];
subView = [[GraphDisplayViewController alloc] init]; <- Mistake