title: Change UI immediately after receiving UIApplicationWillResignActiveNotification
body: <p>I need to make changes in my UI immediately when I receive UIApplicationWillResignActiveNotification. 
   Here is what I do:</p>
  
  <pre><code>[[NSNotificationCenter defaultCenter] addObserver:self
                                           selector:@selector(applicationWillResignActive:)
                                               name:UIApplicationWillResignActiveNotification
                                             object:nil];
  
  
  - (void)applicationWillResignActive:(NSNotification *) notification {
  //    my changes (hide some views, change bg color, change text, etc)
  //    ...
  }
  </code></pre>
  
  <p>The problem is that those changes are applied only after the application returns to the active state. So the user can see for a moment the previous state of UI.
  Is there any workaround to solve this problem?</p>