Question

I have been on an iOS 5 app in which I have an NSOperationQueue which works fine to get some data and create a UIViewController. However, at one point when every operation seems to be complete the app is unresponsive for quite a long time. Here’s how it goes:

1. Get some data from DB
2. Queue – For each item Init a custom UIViewController object.
3. Hand each UIViewController object over to the MainViewController and display them.

Everything goes fine until the UIVC objects have to appear.
It goes past all the [[self view] addSubview:object.view]; and to the end of the function.
But then there is a huge lag, from 5 to 30 seconds before the NSLog statements inside the viewDidApear of the UIVC object show up…

So in code:

//MainViewController
-(void)displayNewView {
  [[self view] addSubview:object.view];
  NSLog(@"Done setup");
}

//-- Long unresponsiveness --//

//UIVC object
-(void)viewDidAppear:(BOOL)animated {
  NSLog(@"Start appear");
  [super viewDidAppear:animated];
}

What could be causing this? Am I missing something obvious?

Thanks for the help!

Answer 1

It seems like it was the complexity of each UIViewController that delayed the whole process.

To me they seem simple but I guess the iPhone doesn’t like creating 10 views at a time with several buttons, labels and images.
Simplifying the nib and making sure only what is used is allocated and initialized helped a lot.. but its still not perfectly fluid.