I'm creating an app where I need to implement WhatsApp like AppBar i.e to hide app bar on scroll down and show on reverse.
You can use the SliverAppBar and CustomScrollView to achieve this effect. A sample implementation:
Widget build(BuildContext context) {
return Scaffold(
body: CustomScrollView(
slivers: <Widget>[
SliverAppBar(
pinned: false,
snap: false,
floating: false,
expandedHeight: 160.0,
flexibleSpace: const FlexibleSpaceBar(
title: Text('AppBar'),
),
),
SliverList(
delegate: SliverChildBuilderDelegate(
(BuildContext context, int index) {
return Container(
color: index.isOdd ? Colors.white : Colors.black12,
height: 100.0,
child: Center(
child: Text('$index', textScaleFactor: 5),
),
);
},
childCount: 50,
),
),
],
),
);
}
Related
I am trying to implement the scrolling effect on the home screen on whatsap on iphone, where the search bar disappears first while scrolling the the rest of the scrolling takes place. Any idea on how to implement it ?
You can try using the SliverAppBar with a CustomScrollView.
return Scaffold(
//1
body: CustomScrollView(
slivers: <Widget>[
//2
SliverAppBar(
expandedHeight: 250.0,
flexibleSpace: FlexibleSpaceBar(
title: Text('Goa', textScaleFactor: 1),
background: Image.asset(
'assets/images/beach.png',
fit: BoxFit.fill,
),
),
),
//3
SliverList(
delegate: SliverChildBuilderDelegate(
(_, int index) {
return ListTile(
leading: Container(
padding: EdgeInsets.all(8),
width: 100,
child: Placeholder()),
title: Text('Place ${index + 1}', textScaleFactor: 2),
);
},
childCount: 20,
),
),
],
),
);
Im so confuse why my sliverappbar doesnt stretch and zoom when I reach the top list. I following the flutter video
https://youtu.be/mSc7qFzxHDw
I tried the following code
class AppBar5 extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: CustomScrollView(
slivers: [
SliverAppBar(
title: Text("title"),
expandedHeight: 200,
stretch: true,
flexibleSpace: FlexibleSpaceBar(
background: Container(
width: MediaQuery.of(context).size.width,
height: 200,
child: Image.asset("assets/images/hot.jpg", fit: BoxFit.cover)
),
)
),
SliverList(
delegate: SliverChildBuilderDelegate(
(_, index) => ListTile(
title: Text("Index: $index"),
),
),
)
],
),
);
}
}
Add Bouncing ScrollPhysics to CustomScrollView
CustomScrollView(
physics: BouncingScrollPhysics(),
...
),
The glow acts like the entire screen is a list. There some way that I can put the glow below the appbar? (edit: without losing the floating effect of the appbar)
CustomScrollView(
slivers: <Widget>[
SliverAppBar(
title: Text('Home Scree'),
floating: true,
leading: Icon(Icons.alarm),
),
SliverList(
delegate: SliverChildBuilderDelegate(
(ctx, i) {
return Column(
children: <Widget>[
ProductCard(),
Divider(
height: 0,
thickness: 1,
),
],
);
},
childCount: 10,
),
),
],
),
Maybe you can try to use NestedScrollView,like this:
#override
Widget build(BuildContext context) {
return Scaffold(
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return [SliverAppBar(
leading: Icon(Icons.alarm),
title: Text('Home Scree'),
expandedHeight: kToolbarHeight,
floating: true,
)];
},
body: ListView.builder(
padding: EdgeInsets.zero,
itemCount: 10,
itemBuilder: (context, index) {
return Column(
children: <Widget>[
ProductCard(),
Divider(
height: 0,
thickness: 1,
),
],
);
}),
),
);
}
I wanna make flutter app.
How to make a moving title on appbar when scrolloing??
I attached app's status on GIF file.
Where do I need to set moving the title text?
I just make app like Uber app
#override
Widget build(BuildContext context) {
double sliderValue = 0.0;
return Scaffold(
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
SliverOverlapAbsorber(
handle: NestedScrollView.sliverOverlapAbsorberHandleFor(context),
child: SliverAppBar(
forceElevated: innerBoxIsScrolled ,
backgroundColor: Colors.transparent,
leading: IconButton(
onPressed: () {
Navigator.pop(context);
},
icon: Icon(Icons.arrow_back),
color: Colors.black,
),
elevation: 0.0,
expandedHeight: 100.0,
floating: false,
pinned: true,
flexibleSpace: FlexibleSpaceBar(
titlePadding: EdgeInsets.only(left: 15.0),
collapseMode: CollapseMode.none,
title: Text("Notification",
style: TextStyle(
color: Colors.black,
fontSize: 20.0,
)),
),
),
),
];
},
body: Center(
child: Text("Sample Text"),
),
),
);
}
Have to use CustomScrollView widget
CustomScrollView(
slivers: <Widget>[
SliverAppBar(
title: Text('Title'),
pinned: true,
expandedHeight: 48,
),
SliverFillRemaining(
child: Center(
child: Text('sliver'),
)),
],
);
I am trying to implement collapsing toolbar in my app using SliverApp bar, but the problem is that the SliverAppBar is overlapping my content when the SliverAppBar is collapsed, I am attaching the gif for more understanding,
the content in the green background is going under the toolbar, I want to avoid that, any leads are appreciated.
#override
Widget build(BuildContext context) {
// TODO: implement buildr
var _tabs = {"1", "2", "3"};
return Scaffold(
backgroundColor: Colors.white,
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
SliverOverlapAbsorber(
handle:
NestedScrollView.sliverOverlapAbsorberHandleFor(context),
child: SliverAppBar(
expandedHeight: 250.0,
floating: false,
pinned: true,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
background: Container(
decoration: BoxDecoration(
shape: BoxShape.rectangle,
image: DecorationImage(
fit: BoxFit.fill,
image: CachedNetworkImageProvider(
newsPost.photos[0].url),
),
),
)),
forceElevated: innerBoxIsScrolled,
))
];
},
body: SafeArea(
top: false,
bottom: false,
child: Builder(
builder: (BuildContext context) {
return CustomScrollView(
slivers: <Widget>[
SliverOverlapInjector(
handle: NestedScrollView.sliverOverlapAbsorberHandleFor(
context),
),
SliverPadding(
padding: const EdgeInsets.all(8.0),
sliver: SliverFillRemaining(child: _getBody()),
),
],
);
},
),
)),
);
}
SliverAppBar Creates a material design app bar that can be placed in a NestedScrollView. Both combinly help us in achieving parallax scrolling.
SafeArea(
child: Scaffold(
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
SliverAppBar(
expandedHeight: 240.0,
floating: false,
pinned: true,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text(
"App Bar",
),
background: Image.network(
"https://images.pexels.com/photos/4148020/pexels-photo-4148020.jpeg",
fit: BoxFit.cover,
)),
),
];
},
body: Center(
child: Text("Hello World!!!"),
),
),
),
);
I think you should use SliverList instead of SliverFillRemaining.
body: SafeArea(
top: false,
bottom: false,
child: Builder(
builder: (BuildContext context) {
return CustomScrollView(
shrinkWrap: true,
slivers: <Widget>[
SliverOverlapInjector(
handle: NestedScrollView.sliverOverlapAbsorberHandleFor(
context),
),
SliverPadding(
padding: const EdgeInsets.all(0.0),
sliver: SliverList(
delegate: SliverChildBuilderDelegate((context, index) {
return Text('Lorem ipsum dolor sit');
}, childCount: 1),
),
),
],
);
},
),
)