UITabBar activity indicator on iPhone

Question

I have a UITabBar + UINavigationController application that often requires data from the Internet. Sometimes it takes quite a while before it works out, so I would like to show an activity indicator.

I am trying to add an ActivityView to my window in my applicationDidFinishLaunching method:

[window addSubview:tabBarController.view];
fullscreenLoadingView.hidden = YES;
[window addSubview:fullscreenLoadingView];

And then I add the application delegate as an observer to the default notification center:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(startFullscreenLoading:) name:@"startFullscreenLoading" object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(stopFullscreenLoading:) name:@"stopFullscreenLoading" object:nil];

and implement the methods:

- (void)startFullscreenLoading:(NSNotification *)notification {
    fullscreenLoadingView.hidden = NO;
}

- (void)stopFullscreenLoading:(NSNotification *)notification {
    fullscreenLoadingView.hidden = YES;
}

When I use this directly in the applicationDidFinishLaunching method, upp is displayed in the load indicator view as expected:

[[NSNotificationCenter defaultCenter] postNotificationName:@"startFullscreenLoading" object:self];

But when I use it from one of the navigation controllers, the startFullscreenLoading: method is called, but I do not see the type of the loading indicator. Why is this?

Answer 1

? .

Answer 2

, , .

[[fullScreenLoadingView superView] bringSubviewToFront:fullScreenLoadingView]

, -startFullscreenLoading, , fullscreenLoadingView .

Answer 3

, UIActivityView IB , ( ). , .

[activityIndicator startAnimating] [activityIndicator stopAnimating];