UINavigationController pushViewController pauses/freezes midway through

Question

I am pushing a view controller via:

[self.navigationController pushViewController:[[UIViewController alloc] init] animated:YES];

But the animation lags/pauses a for half a second mid way through. The animation is not complete. Here's the gif;

enter image description here

Have you tried allocating the `UIViewController` *before* pushing to it? — msgambel, Nov 11 '13 at 23:31
@msgambel it is allocated before it's pushed. The inner expression is evaluated first, then outer. I haven't tried but I don't see how that makes a difference...it's the same thing. — 0xSina, Nov 11 '13 at 23:36
@0xSina No idea then. Maybe you're having memory allocation issues because too much is running? Have you tried turning on slow animations to see what's going on? — msgambel, Nov 11 '13 at 23:54
+1 for the animated GIF. I had the exact same symptom. Setting an opaque background color fixed it for me too, but I really wish I knew why. — cduhn, Apr 29 '16 at 18:48

Vincent Bernier · Accepted Answer · 2013-11-13T19:59:21.887

54

With out more detail I can think of 2 possible problem with that.

Is there Shadow added in code to the view that will be covered by the new ViewController. If it is the case, use ShadowPath or an translucent view instead (the property Shadow is expensive while animating, been there done that)
Is the backgroundColor of new ViewController "clearColor" ? I've seen strange rendering problem with that kind of thing.

Try:

UIViewController *vc = [[UIViewController alloc] init];  
vc.view.backgroundColor = [UIColor whiteColor];  
[self.navigationController pushViewController:vc animated:YES];

That is the 2 possible problems I can think of the top of my head with so few detail.

Never rely on the default background color, it has change with iOS version and is not consistant across controls and can even be different if the view is created in code or from a Xib (in the same iOS version).

edited Nov 13 '13 at 19:59

answered Nov 12 '13 at 01:07

Vincent Bernier

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The background color was not set so it was I guess 'default' (is that clear?). Regardless, changing the presented view controller to whiteColor fixed the problem. thanks. – 0xSina Nov 12 '13 at 19:13
4

Setting the background color also did it for me. – Lasse Bunk Jan 14 '14 at 21:51
http://stackoverflow.com/questions/8833631/pushviewcontroller-animation-is-slow-choppy – len Jul 01 '15 at 08:30
Thanks a lot man .. Color if the view was clear that was blocking the transition. thats weird. – Kunal Gupta Jan 03 '17 at 13:05
It's 2021 and this was still the solution. Thanks!! – Mike Taverne May 22 '21 at 06:47

Brian Green · Answer 2 · 2018-08-05T20:10:10.547

1

In app delegate, set your window's background color to white.

window?.backgroundColor = .white

Also in the the pushed view controller, set its view to white.

view.backgroundColor = .white

I experienced the same issue when programmatically embedding my view controller in a UINavigationController.

edited Aug 05 '18 at 20:10

answered Aug 05 '18 at 19:58

Brian Green

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score 0 · Answer 3 · edited May 23 '17 at 12:10

0

While setting the background color as suggested by VinceBurn solved the pausing, it made the entire animation white, fading in the actual content only when the animation finished.

For me the problem was solved by making sure the content was correctly sized in -viewDidLoad.

edited May 23 '17 at 12:10

Community

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answered Mar 08 '16 at 16:39

Barak Yoresh

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UINavigationController pushViewController pauses/freezes midway through

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