NavigationBarとStatusBarを半透明にして全画面表示にする

- (void)loadView
{
  [super loadView];
  
  // loadViewで設定しないとviewDidLoadでサイズが全画面仕様にならない
  [UIApplication sharedApplication].statusBarStyle = UIStatusBarStyleBlackTranslucent;
  self.navigationController.navigationBar.barStyle = UIBarStyleBlackTranslucent;
  self.navigationController.navigationBar.translucent = YES;
  self.wantsFullScreenLayout = YES;
}

- (void)viewWillAppear:(BOOL)animated
{
  [super viewWillAppear:animated];
  
  // navigationがpopされて戻ってきた時用
  [UIApplication sharedApplication].statusBarStyle = UIStatusBarStyleBlackTranslucent;
  self.navigationController.navigationBar.barStyle = UIBarStyleBlackTranslucent;
  self.navigationController.navigationBar.translucent = YES;
  self.wantsFullScreenLayout = YES;
}

- (void)viewWillDisappear:(BOOL)animated
{
  [super viewWillDisappear:animated];
  
  // 全画面表示を戻す
  [UIApplication sharedApplication].statusBarStyle = UIStatusBarStyleDefault;
  self.navigationController.navigationBar.barStyle = UIBarStyleDefault;
  self.navigationController.navigationBar.translucent = NO;
  self.wantsFullScreenLayout = NO;
}