Help me understand leaks on this code: [duplicate] - iphone

Question

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Closed 11 years ago.
Possible Duplicate:
How to release an object declared into a method and passed to another method?
Can you help me fix leaks in this code:
- (void)connectionDidFinishLoading:(NSURLConnection *)connection
{
UIImage *payload = [[UIImage alloc] initWithData:self.activeDownload];
UIImage *picture = [[UIImage alloc] init];
if (payload.size.width != kAppIconHeight && payload.size.height != kAppIconHeight)
{
CGSize itemSize = CGSizeMake(kAppIconHeight, kAppIconHeight);
UIGraphicsBeginImageContext(itemSize);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
[payload drawInRect:imageRect];
picture = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
else
{
picture = payload;
}
self.activeDownload = nil;
[payload release];
self.imageConnection = nil;
[delegate ThumbDidLoad:self.indexPathInTableView Image:[picture autorelease]];
}
Thx for helping,
Stephane

Answer 1

When you set picture = UIGraphicsGetImageFromCurrentImageContext() in your if statement or picture = payload in your else statement, you are loosing the pointer to the previously allocated UIImage you assigned in picture in the first lines, but you never released it.
You shouldn't alloc+init a new UIImage for picture, as you never use it and assign a new value to this variable later... but never used and released the previously allocated one.

Answer 2

UIImage *picture = [[UIImage alloc] init]; and picture = UIGraphicsGetImageFromCurrentImageContext();
You should not initialize picture at the beginning of the code. UIGraphicsGetImageFromCurrentImageContext returns a already initialized UIImage (autoreleased).
UIImage *payload = [[UIImage alloc] initWithData:self.activeDownload];, picture = payload;, [payload release];.
You should use [payload autorelease] instead, otherwise you're releasing the image without ever using it.
[delegate ThumbDidLoad:self.indexPathInTableView Image:[picture autorelease]];
You should remove [picture autorelease] and just use picture.
-(void)connectionDidFinishLoading:(NSURLConnection *)connection{
UIImage *payload = [[UIImage alloc] initWithData:self.activeDownload];
UIImage *picture;
if (payload.size.width != kAppIconHeight && payload.size.height != kAppIconHeight)
{
CGSize itemSize = CGSizeMake(kAppIconHeight, kAppIconHeight);
UIGraphicsBeginImageContext(itemSize);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
[payload drawInRect:imageRect];
picture = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
else
{
picture = payload;
}
[payload autorelease];
self.activeDownload = nil;
self.imageConnection = nil;
[delegate ThumbDidLoad:self.indexPathInTableView Image:picture];
}