CODEWITHSUNDEEP
iphoneiosmemory-management
Nielsou Hacken-Bergen
Nielsou Hacken-Bergen

Reputation: 2626

Memory management question

Is there a memory leaks when I set an attribut in this way : 

titleView = [[UIWebView alloc] initWithFrame:CGRectMake(10, 0, 300, 5)];

And is there a difference with

UIWebView *newWebView = [[UIWebView alloc] initWithFrame:CGRectMake(10, 0, 300, 5)];
[self setTitleView:newWebView];
[newWebView release];

Thanks,

EDIT : I'm releasing the titleView in the dalloc function

Upvotes: 0

Views: 89

Answers (4)

rckoenes
rckoenes

Reputation: 69499

Assuming that you have declared the proerty correctly:

@property (nonatomic, retain) UIWebView *titleView;

if do:

self.titleView = [[UIWebView alloc] initWithFrame:CGRectMake(10, 0, 300, 5)];

then you leak but when you do it direct in the ivar like:

titleView = [[UIWebView alloc] initWithFrame:CGRectMake(10, 0, 300, 5)];

The you are ok.

But you need to release it in the dealloc:

- (void)dealloc {
    [titleView release], titleView = nil;
    [super dealloc];
}

Upvotes: 0

Eimantas
Eimantas

Reputation: 49354

Do not confuse attribute with instance and/or local variable. An attribute (or property) is accessed via self, while instance variable is accessed directly by it's name.

In first example there's a leak since I can't see the release message sent to titleView. If titleView is instance variable you'd release it in viewDidUnload method. If it's local - you should release it when adding to some view (like in second example).

In the second example there is no memory leak.

Upvotes: 0

Deniz Mert Edincik
Deniz Mert Edincik

Reputation: 4363

Assuming you have a property called titleView.

@property (retain) titleView

First one leaks, unless you release it on dealloc (but beware if you are assigning it more than once)

correct one should be: 

self.titleView =  [[[UIWebView alloc] initWithFrame:CGRectMake(10, 0, 300, 5)] autorelease];

it is always good practice to use self.propertyName as it also releases the old value.

Upvotes: 1

Nekto
Nekto

Reputation: 17877

If titleView is declined without retain attribute then there is difference.

In first case there will be all ok. In second one - you can't use titleView after [newWebView release].

Upvotes: 0

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