You can use KVO to do that. In viewDidLoad
of AUIController
add this code [self.navigationController.navigationBar addObserver:self forKeyPath:@"alpha" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:(__bridge void *)(self)];
and implement this function:
-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
NSLog([change description]);
UIViewController *viewController = (__bridge UIViewController*)context;
if ([viewController isKindOfClass:[AUIViewController class]]) {
if (self.navigationController.navigationBar.alpha == 1) {
self.navigationController.navigationBar.alpha = 0.500;
self.navigationController.navigationBar.translucent = YES;
}
}
}