title: How to detect Dynamic Font size changes from iOS Settings?
body: <p>Inside settings->general->text size, after changing the text size, I'd have to exit my own app to have the sizes applied to</p>
  
  <pre><code> [UIFont preferredFontForTextStyle:..]
  </code></pre>
  
  <p>Is there a delegate or notification to notify my app to re-apply the new sizes?</p>
  
  <p>Update: I tried the following but interestingly, the font size will apply after I BG and launch the app TWICE.</p>
  
  <pre><code>- (void)viewDidLoad
  {
  [super viewDidLoad];
  // Do any additional setup after loading the view, typically from a nib.
  
  
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(fromBg:) name:UIApplicationDidBecomeActiveNotification object:nil];
  
  }
  
  
   -(void) fromBg:(NSNotification *)noti{
  
      self.headline1.font = [UIFont preferredFontForTextStyle:UIFontTextStyleHeadline];
      self.subHeadline.font = [UIFont preferredFontForTextStyle:UIFontTextStyleSubheadline];
      self.body.font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
      self.footnote.font = [UIFont preferredFontForTextStyle:UIFontTextStyleFootnote];
      self.caption1.font = [UIFont preferredFontForTextStyle:UIFontTextStyleCaption1];
      self.caption2.font = [UIFont preferredFontForTextStyle:UIFontTextStyleCaption2];
  //    [self.view layoutIfNeeded];
  
  }
  </code></pre>