Why does UIIndicator not move away?

Question

I use UIActivityIndicator in my app. I have written code for it as follows:

-(void)startSpinner {
    
    spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
    spinner.hidden = NO;
    spinner.frame = CGRectMake(137, 160, 50, 50);
    [spinner setHidesWhenStopped:YES];
    [self.view addSubview:spinner];
    [self.view bringSubviewToFront:spinner];
    [spinner startAnimating];
}

I call this method on the UIButton's action event, and to remove indicator I write the code as follows:

-(void)stopSpinner {
    
    [spinner stopAnimating];
    [spinner removeFromSuperview];
    [spinner release];
}

on click on the button indicator appears but when I call -(void)stopSpinner method in view willAppear the indicator does not disapppear.

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [self stopSpinner];
   
}

Even I debug the code and I found that control also goes to the stopSpinner().

What is the problem here?

Try making the UIIndicator in Interface Builder and see if you get the same situation. — SimplyKiwi, Nov 25 '11 at 06:58
Check the address of spinner when you start it and when you stop it. I have a feeling that when you stop it, the `spinner` variable in your `stopSpinner` method is null. — Michael Dautermann, Nov 25 '11 at 06:59
Are all these methods in the same instance of the same class? Can you give use some idea of the order of operations here - I can't picture how you would be starting a spinner and then wanting to stop it in the same viewcontroller's viewwillappear method? — jrturton, Nov 25 '11 at 09:05

score 3 · Accepted Answer · answered Nov 25 '11 at 09:03

You might have potential leak in startSpinner because you always create UIActivityIndicatorView without releasing it. Change your method like this:

-(void)startSpinner {
    if (spinner){
        [spinner removeFromSuperview];
        [spinner release]; spinner = nil;
    }
    spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
    spinner.frame = CGRectMake(137, 160, 50, 50);
    [spinner setHidesWhenStopped:YES];
    [self.view addSubview:spinner];
    [spinner startAnimating];
}

For stopping animation assign stopSpinner for another UIButton action. Cos viewWillAppear will fired early then you tap on any button.
ps. maybe you mean viewWillDisappear?

Why does UIIndicator not move away?

1 Answers1