title: How to refresh preferredStatusBarStyle in one ViewController for two or more times
body: <p>My old code :</p>
  
  <pre><code>- (void)setStatusBarLight:(BOOL)value {
      if (value) {
          [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
      } else {
          [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleDefault];
      }
  }
  </code></pre>
  
  <p>Now setStatusBarStyle is deprecated. Apple says, that i should use <strong>preferredStatusBarStyle</strong>. But this calls only once. But in my option status bar must change color after some user actions in this view controller.</p>
  
  <p>What can I do ? </p>