CupertinoNavigationBar constructor

const CupertinoNavigationBar({Key key, Widget leading, bool automaticallyImplyLeading: true, bool automaticallyImplyMiddle: true, String previousPageTitle, Widget middle, Widget trailing, Border border: _kDefaultNavBarBorder, Color backgroundColor: _kDefaultNavBarBackgroundColor, EdgeInsetsDirectional padding, Color actionsForegroundColor: CupertinoColors.activeBlue, bool transitionBetweenRoutes: true, Object heroTag: _defaultHeroTag })

Creates a navigation bar in the iOS style.

Implementation 

const CupertinoNavigationBar({
  Key key,
  this.leading,
  this.automaticallyImplyLeading = true,
  this.automaticallyImplyMiddle = true,
  this.previousPageTitle,
  this.middle,
  this.trailing,
  this.border = _kDefaultNavBarBorder,
  this.backgroundColor = _kDefaultNavBarBackgroundColor,
  this.padding,
  this.actionsForegroundColor = CupertinoColors.activeBlue,
  this.transitionBetweenRoutes = true,
  this.heroTag = _defaultHeroTag,
}) : assert(automaticallyImplyLeading != null),
     assert(automaticallyImplyMiddle != null),
     assert(transitionBetweenRoutes != null),
     assert(
       heroTag != null,
       'heroTag cannot be null. Use transitionBetweenRoutes = false to '
       'disable Hero transition on this navigation bar.'
     ),
     assert(
       !transitionBetweenRoutes || identical(heroTag, _defaultHeroTag),
       'Cannot specify a heroTag override if this navigation bar does not '
       'transition due to transitionBetweenRoutes = false.'
     ),
     super(key: key);