Question

I have a button on the iPhone interface that performs a function. The function is this:

-(IBAction)courses:(id)sender {
[loading startAnimating];
[connection getCourses];
[outlet setText:connection.lastResponseData];
}

My problem is that the animation only starts after the [outlet setText:connection.lastResponseData. How can I get the loading to start animating before that?

Thanks.

Answer 1

It looks like getCourses is blocking the main thread; any animations you start will be deleted until after courses: returns. Modify your code to use a background thread:

-(IBAction)courses:(id)sender {
[loading startAnimating];
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        [connection getCourses];
        dispatch_async(dispatch_get_main_queue(), ^{
            [outlet setText:connection.lastResponseData];       
            [loading stopAnimating];
        });
    });
}

This will put your blocking network access in a system-provided background GCD queue, which wraps a background thread.