Question

I have a UIPopoverViewController that is displaying a custom UIViewController properly. When I click a button I have an action run and as a result I add a view to the view hierarchy of the UIViewController’s view.

The problem is that it is very slow, and takes several seconds for the view to appear. I’m not doing anything out of the ordinary with my UIViewController’s code.

- (void)showAccountChooser {
    self.twitterAccountPicker = [TwitterAccountPicker new];
    [self.view addSubview:self.twitterAccountPicker.view];
    self.twitterAccountPicker.view.frame = self.view.bounds;

    self.twitterAccountPicker.view.transform = CGAffineTransformMakeScale(.05, .05);

    [UIView animateWithDuration:0.5f animations:^{
        self.twitterAccountPicker.view.transform = CGAffineTransformMakeScale(1, 1);
    } completion:^(BOOL finished) {
        //[self.twitterAccountPicker viewDidAppear:YES];
    }];
}

The UIViewController that I’m adding is trivial and does not heavy processing in the viewDidLoad or viewWill/DidAppear. I have set break points and verified that it is not doing anything bad.

Anyone else notice this when adding views?

Answer 1

After setting break points trying to debug this, I realized that my showAccountChooser method was being called from a block invoke, which was happening on a background thread. Moving this call to the main thread resolved the issue.