Delay when updating view in the completionHandler of an async HTTP request

Question

In my app when the user presses a button I start a HTTP asynchronous request (using [NSURLConnection sendAsynchronousRequest...]) and change the text of U

Answer 1

This could happen because all UI stuff should be called in a main queue. Try this:

- (IBAction)requestStuff:(id)sender 
{
    NSURL *url = [NSURL URLWithString:@"http://stackoverflow.com/"];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];
    NSOperationQueue *queue = [[[NSOperationQueue alloc] init] autorelease];

    [NSURLConnection sendAsynchronousRequest:request queue:queue completionHandler:
     ^(NSURLResponse *response, NSData *data, NSError *error) 
     {
         NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response;          

         dispatch_async(dispatch_get_main_queue(), ^{
             exampleLabel.text = [NSString stringWithFormat:@"%d", httpResponse.statusCode];
         });
     }];    
}