UIAppearance subview disappears from Navigationbar - uiview

Question

I'm doing some changes to the Navigationbar with appearance in appdelegate.
This is my method:
-(void) setAppearance{
NSMutableDictionary *titleBarAttributes = [NSMutableDictionary dictionaryWithDictionary: [[UINavigationBar appearance] titleTextAttributes]];
[titleBarAttributes setValue:[UIFont fontWithName:#"AvantGarde-ExtraLight" size:18] forKey:NSFontAttributeName];
[titleBarAttributes setValue:[UIColor whiteColor] forKey:NSForegroundColorAttributeName];
[[UINavigationBar appearance] setTitleTextAttributes:titleBarAttributes];
[[UINavigationBar appearance] setBarTintColor:[UIColor colorWithRed:6.0/256.0 green:57.0/256.0 blue:84.0/256.0 alpha:1.0]];
[[UINavigationBar appearance] setTintColor:[UIColor whiteColor]];
int borderSize = 3;
UIImageView *navBorder = [[UIImageView alloc] initWithFrame:CGRectMake(0,
41,
320,
borderSize)];
navBorder.image = [UIImage imageNamed:#"energy_line"];
navBorder.tag = 999;
[[UINavigationBar appearance] addSubview:navBorder];
[[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
}
I have a method in my appdelegate that sets the window to my first viewController, when i call this method, my navBorder is removed from the navigationbar. I don't understand why this happens, there is no code that changes anything in my navigationbar in the viewcontroller.
- (void)rootView
{
[self.window setRootViewController:initialViewController];
}

Answer 1

I answered pretty much the same question here: https://stackoverflow.com/a/26414437/538491
But here is a summary:
Calling [[UINavigationBar appearance] returns an appearance proxy for the receiver class. The addSubview: method is not tagged as UI_APPEARANCE_SELECTOR. One major downside to UIAppearance's proxy approach is that it's difficult to know which selectors are compatible.
You should get a hold of the navigation bar and add the image there by calling this method: [self.navigationController.navigationBar addSubview:navBorder] or you should subclass UINavigationBar which gives you more flexibility.