Activity Indicator stop animation has no effect

Question

So basically i have a activity indicator that i start like this before sending an async request

[self.activityIndicator setBounds:self.view.frame];
[self.activityIndicator setCenter:self.view.center];
[self.activityIndicator setAlpha:1.0f];
UIColor *activityBackgroundColor = [UIColor colorWithRed:0.5 green:0.5 blue:0.5 alpha:0.3];
[self.activityIndicator setBackgroundColor:activityBackgroundColor];
[self.activityIndicator startAnimating];

[self sentRequestToFacebook];
[calender returnCalenderEvents];

The completion handlers for the async request notify the main object object using NSNotification to stop the activity indicator which i do like this

if ([[notification name]isEqualToString:@"calenderData"]) {
    calenderDataReceived = YES;
    NSDictionary* userInfo = notification.userInfo;
    calendarData = [userInfo objectForKey:@"data"];
}
else if ([[notification name]isEqualToString:@"facebookData"])
{
    facebookDataReceived = YES;
    NSDictionary* userInfo = notification.userInfo;
    facebookData = [userInfo objectForKey:@"data"];
}

if (facebookDataReceived&&calenderDataReceived) {
    facebookDataReceived = NO;
    calenderDataReceived = NO;
    //Now do the mergings
    self.activityIndicator.hidden = YES;
    [self.activityIndicator stopAnimating];
    [self.activityIndicator removeFromSuperview];
    NSLog(@"%@",calendarData);
    NSLog(@"%@",facebookData);
}

However this code didn't has the desired effect and the activity indicator would still animate for a few seconds after the running of this code before stopping.

What's the problem here

Answer 1

If the indicator stops after a few seconds, then make sure that the code that stops the indicator runs on the main thread. if it runs on a different thread then use this snippet:

dispatch_async(dispatch_get_main_queue(), ^{
    self.activityIndicator.hidden = YES;
    [self.activityIndicator stopAnimating];
    [self.activityIndicator removeFromSuperview];
})