Delay in presenting a modal view controller

It seems calling presentViewController:animated:completion from within tableView:didSelectRowAtIndexPath: is problematic. It's difficult to find anything that stands out when using the Time Profiler in Instruments, also. Sometimes my modal view comes up in less than a second and other times it takes 4s or even 9s.

I think it's related to the underlying UIPresentationController and layout, which is one of the few things I see when selecting the region of time between tapping on a row and seeing the modal presentation in the Time Profiler.

A Radar exists describing this issue: http://openradar.appspot.com/19563577

The workaround is simple but unsatisfying: delay the presentation slightly to avoid whatever contentious behavior is causing the slowdown.

dispatch_async(dispatch_get_main_queue(), ^{
   [self presentViewController:nav animated:YES completion:nil];
});

If you call present(:animated:completion:) in tableView(:didSelectRowAt:), selectionStyle == .none for selected tableview cell and you’ve got this strange behavior then try to call tableView.deselectRow(at:animated:) before any operations in tableView(_:didSelectRowAt:).

Did it help?

Swift 4: you can use as below.

DispatchQueue.main.async {
            let popUpVc = Utilities.viewController(name: "TwoBtnPopUpViewController", onStoryboard: "Login") as? TwoBtnPopUpViewController
            self.present(popUpVc!, animated: true, completion: nil)
        }

It works for me.

I guess you also set the cell's selectionStyle to UITableViewCellSelectionStyleNone. I change to UITableViewCellSelectionStyleDefault and it work perfect.

You should display it modally from your root vc (e.g: customTabBarRootViewController). save a reference, and use the reference controller to display it.