Question

I have two views, first one “A”, has a button that trigger a web service to validate one code, if validation is successful, it performs a segue to the view “B”.

In view B, I have this

- (bool) viewDidUpload

   dispatch_async(kBgQueue, ^{


    [self processContacts];
    [self sendPost];
});



-(void) processContacts

    //Process contact address

-(void) sendPost
    //Process web services call
    //If web service call is OK, call [self updateBar]
            [self performSelectorOnMainThread:@selector(updateBar) 
                               withObject:nil waitUntilDone:YES];

UPDATED: I implemented GDC to send sendPost and processContacts in the background, then sendPost method has the updateBar call performed using performSelectorOnMainThread:, the problem is that the execution doesn’t enter in this method and it finishes without updating the bar. sendPost and processContacts now run in the background, but I don’t know how to perform updateBar in the main every time a valid connection is done, and then return to the background and perform rest of connections and again.

Many thanks

Answer 1

You should perform all calculations and communications in background thread. Then do updates on GUI stuff (like progress bar) in your main thread.

Take a look at GCD. It is really easy to use and will solve your problem I’m sure.