How to make custom SliverAppBar in Flutter?

Issue

Sliver App Bar

Hello I guys, I am working on Sliver Appbar but I want this type of custom SliverAppbar,How can I achieve this?

Solution

You can try to simulate the same using SliverPersistentHeader Widget and a bunch of slivers included inside the CustomScrollView. All you need to do is give the AppBar, the SliverPersistentHeader and the first Sliver the same background color.

Have a look at the code below (sorry for the bad formatting). I have also included a gif in the end as how it looks (sorry for the bad design).

  class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: _title,
      home: MyStatefulWidget(),
      debugShowCheckedModeBanner: false,
    );
  }
}

class MyStatefulWidget extends StatefulWidget {
  const MyStatefulWidget({Key? key}) : super(key: key);

  @override
  State<MyStatefulWidget> createState() => _MyStatefulWidgetState();
}

class _MyStatefulWidgetState extends State<MyStatefulWidget> {

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(backgroundColor:  const Color(0xff222222),
                     title: const Text("JazzCash"),
                     elevation: 0,
                    actions: const [Icon(Icons.info), Icon(Icons.notifications)]),
      body: CustomScrollView(
        slivers: <Widget>[
          
          // persistent header
          SliverPersistentHeader(
            pinned: true,
            delegate: SliverAppBarDelegate(
        minHeight: 60.0,
        maxHeight: 60.0,
        child: Container(
            color: const Color(0xff222222), child:Row(children:
                const [SizedBox(width: 10), CircleAvatar(), SizedBox(width: 10), Text("Muhammad", style: TextStyle(fontSize: 20, color: Colors.white)),
                ])),
      ),
         ),
          SliverList(
          delegate: SliverChildListDelegate(
            [
              
              // first sliver
              Container(color: const Color(0xff222222), 
                  padding: const EdgeInsets.all(10),
                  child: Column(crossAxisAlignment: CrossAxisAlignment.start,
                                                                children: [const Text("Login -->", style: TextStyle(color: Colors.amber, fontSize: 25, fontWeight: FontWeight.bold)),
                                                                           const Text("to Make Payments", style: TextStyle(color: Colors.white, fontSize: 25, fontWeight: FontWeight.bold)),
                                                                           const SizedBox(height: 10),
                                                                           Row(children: [ElevatedButton(onPressed: (){}, child: const Text("Add money")), const SizedBox(width: 20), ElevatedButton(onPressed: (){}, child: const Text("Add account"))])
                                                                          ])),
              Container(color: Colors.purple, height: 150.0),
              Container(color: Colors.green, height: 150.0),
        ],
        ),
        ),
        ],
      ),
    );
  }
}

// defining delegate for sliverpersistendheader
class SliverAppBarDelegate extends SliverPersistentHeaderDelegate {
  SliverAppBarDelegate({
    @required this.minHeight,
    @required this.maxHeight,
    @required this.child,
  });
  final double? minHeight;
  final double? maxHeight;
  final Widget? child;
  @override
  double get minExtent => minHeight!;
  @override
  double get maxExtent => math.max(maxHeight!, minHeight!);
  @override
  Widget build(
      BuildContext context, 
      double shrinkOffset, 
      bool overlapsContent) 
  {
    return SizedBox.expand(child: child);
  }
  @override
  bool shouldRebuild(SliverAppBarDelegate oldDelegate) {
    return maxHeight != oldDelegate.maxHeight ||
        minHeight != oldDelegate.minHeight ||
        child != oldDelegate.child;
  }
}

Answered By - CYBERDEVILZ