Label or Text Dynamic Type

iOSDynamicFontSizeChange

-(void) doDynamicTypeThings{
    self.someHeadline.font = [UIFont preferredFontForTextStyle:UIFontTextStyleHeadline];
    self.someBodyTextLabel.font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
}

- (void)viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(preferredContentSizeChanged:)
                                                 name:UIContentSizeCategoryDidChangeNotification
                                               object:nil];
    [self doDynamicTypeThings];
}

- (void)preferredContentSizeChanged:(NSNotification *)notification{
    [self doDynamicTypeThings];
    [self.view setNeedsLayout];
}

-(void) viewWillDisappear:(BOOL)animated{
    [super viewWillDisappear:animated];
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}