Loading animation Memory leak

Question

Hi, I have written network class that is managing all network calls for my application. There are two methods showLoadingAnimationView and hideLoadingAnimationView that will show UIActivityIndicatorView in a view over my current viewcontroller with fade background. I am getting memory leaks somewhere on these two methods. Here is the code

-(void)showLoadingAnimationView
{ 
    textmeAppDelegate *textme = (textmeAppDelegate *)[[UIApplication sharedApplication] delegate];
    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES];
    if(wrapperLoading != nil)
    {
        [wrapperLoading release];
    }
    wrapperLoading = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, 320.0, 480.0)];
    wrapperLoading.backgroundColor = [UIColor clearColor];
    wrapperLoading.alpha = 0.8;

    UIView *_loadingBG = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, 320.0, 480.0)];
    _loadingBG.backgroundColor = [UIColor blackColor];
    _loadingBG.alpha = 0.4;

    circlingWheel = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
    CGRect wheelFrame = circlingWheel.frame;
    circlingWheel.frame = CGRectMake(((320.0 - wheelFrame.size.width) / 2.0), ((480.0 - wheelFrame.size.height) / 2.0), wheelFrame.size.width, wheelFrame.size.height);
    [wrapperLoading addSubview:_loadingBG]; 
    [wrapperLoading addSubview:circlingWheel];
    [circlingWheel startAnimating];
    [textme.window addSubview:wrapperLoading];
    [_loadingBG release];
    [circlingWheel release];
}

-(void)hideLoadingAnimationView
{   
    [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
    wrapperLoading.alpha = 0.0;

    [self.wrapperLoading removeFromSuperview];
    //[NSTimer scheduledTimerWithTimeInterval:0.8 target:wrapperLoading selector:@selector(removeFromSuperview) userInfo:nil repeats:NO];
}

Here is how I am calling these two methods

[NSThread detachNewThreadSelector:@selector(showLoadingAnimationView) toTarget:self withObject:nil];

and then somewhere later in the code i am using following function call to hide animation.

[self hideLoadingAnimationView];

I am getting memory leaks when I call showLoadingAnimationView function. Anything wrong in the code or is there any better technique to show loading animation when we do network calls?

Answer 1

The method showLoadingAnimationView returns a non auto-released view (retainCount -> 1), that you later (I assume) add to another view (retainCount -> 2).

In hideLoadingAnimationView, you only remove the view from its superview (retainCount -> 1). There is a missing release in this method. That means that you should not call release in the showLoadingAnimationView.