isAlwaysShown property Null safety

bool? isAlwaysShown
final

Indicates that the scrollbar should be visible, even when a scroll is not underway.

When false, the scrollbar will be shown during scrolling and will fade out otherwise.

When true, the scrollbar will always be visible and never fade out. This requires that the Scrollbar can access the ScrollController of the associated Scrollable widget. This can either be the provided controller, or the PrimaryScrollController of the current context.

Defaults to false when null.

final ScrollController _controllerOne = ScrollController();
final ScrollController _controllerTwo = ScrollController();

Widget build(BuildContext context) {
return Column(
  children: <Widget>[
    SizedBox(
       height: 200,
       child: Scrollbar(
         isAlwaysShown: true,
         controller: _controllerOne,
         child: ListView.builder(
           controller: _controllerOne,
           itemCount: 120,
           itemBuilder: (BuildContext context, int index) {
             return  Text('item $index');
           },
         ),
       ),
     ),
     SizedBox(
       height: 200,
       child: CupertinoScrollbar(
         isAlwaysShown: true,
         controller: _controllerTwo,
         child: SingleChildScrollView(
           controller: _controllerTwo,
           child: const SizedBox(
             height: 2000,
             width: 500,
             child: Placeholder(),
           ),
         ),
       ),
     ),
   ],
  );
}

See also:

Implementation

final bool? isAlwaysShown;