在容器视图（Storyboard）中推入透明背景UIViewController时为灰色背景

Question

I'm pushing a UIViewController ( A ) with clearColor as background in a UINavigationController ( N ).

N is placed inside a Container View. This view has a background that I want to show always.

Then, when Push is animated it shows a grey/transparent background in my VC ( A ) and when it finishes its animation, it shows correctly.

Is there any way to avoid this grey color?

I have 'done' it by putting a white view background in A and making it disappear in viewDidAppear but I think it can be done without that trick...

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    __weak TestsViewController *weakSelf = self;
    [UIView animateWithDuration:.3 animations:^{
        TestsViewController *ownSelf = weakSelf;
        ownSelf.backgroundView.alpha = 0;
    }];
}

Answer 1

Set your app's window's background colour to white:

// applicationDidFinishLaunching
self.window.backgroundColor = [UIColor whiteColor];

The push animation often ends up using the background colour of the window behind the transparent areas, and the window background colour is clear by default, so it shows black through the transparent navigation bars and toolbars.

EDIT : Sorry, misunderstood what the issue was. When you push a view controller with a transparent background colour, the background you see behind the view controller is the shadow that is rendered behind your view controller (you can see the edge of it when in a non-transparent view controller).

This question has an answer to your issue. Basically, you have to implement a custom animation controller, to provide the transition animation yourself (as described here ). It would probably be easier to continue using your trick than implementing your own custom navigation transition.