Question

Can someone point me in the right direction. When I load this file in as a nib, and unload it, and reload it instruments says I’m getting a memory leak. Specifically, it’s says that where I set the compareOptions NSMutableArray, and where I call [vc release].
CompareOptions is a synthesize property that is also released in the dealloc.
Many thanks in advance.

- (void)viewDidLoad{
[super viewDidLoad];

//NSLog(@"Comparison.viewDidLoad");

self.compareOptions = [[NSMutableArray alloc] init];


self.tabs = [[ComparisonTabs alloc] initWithFrame:CGRectMake(450, 85, 650, 50)];

    //NSDictionary  * currComparison    = (NSDictionary*)[data objectAtIndex:0];
    //NSArray           * correctOptions    = [currComparison objectForKey:@"correct"];

for(int i = 0; i < 3; i++)
{
    UIViewController * vc = [[UIViewController alloc] initWithNibName:@"ComparisonOptions" bundle:nil];

    ComparisonOptions * options = (ComparisonOptions *)vc.view;

    [options setup];
    options.index = i;

    //options.frame = CGRectMake(355 + (306 * i), 475, options.frame.size.width, options.frame.size.height);

    //[options setCorrect:[correctOptions objectAtIndex:i]];

    [vc release];

    [self.view addSubview:options];

    [self.compareOptions addObject:options];
}

[self.view addSubview:self.tabs];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(tabSelectedHandler:) name:@"tabSelected" object:nil ];

[self update:0];}

Answer 1

how does the property of compareOptions and tabs look like? Does it retain your objects?

If it does retain, then you’ll get a double retain if you use the setter and alloc.

self.compareOptions = [[NSMutableArray alloc] init];
    ^ retains                          ^^^^^ retains

self.tabs = [[ComparisonTabs alloc] initWithFrame:CGRectMake(450, 85, 650, 50)];
    ^ retains                ^^^^^ retains

you could use this instead

self.compareOptions = [NSMutableArray array];
self.tabs = [[[ComparisonTabs alloc] initWithFrame:CGRectMake(450, 85, 650, 50)] autorelease];

---

UIViewController * vc = [[UIViewController alloc] initWithNibName:@"ComparisonOptions" bundle:nil];
ComparisonOptions * options = (ComparisonOptions *)vc.view;

[vc release];

[self.view addSubview:options];

vc.view (ie options) will be deallocated at the same time vc will be deallocated. And this happens when you call [vc release]. You can’t use options after this.

You should release vc after you’ve added the view to the subview.

---

And you should think about better class names. I would never assume that ComparisonOptions is a View. It sounds more like NSCaseInsensitiveSearch etc. You know, like it would be an option.