Why CustomScrollView is not detecting scrolling - flutter

I am using CustomScrollView inside Scaffold ,dont't know why it's not detecting Scrolling behaviour.
Widget build(BuildContext context) {
return Scaffold(
body: CustomScrollView(
slivers: <Widget>[
// SliverAppBar(floating: true,),
SliverAppBar(
expandedHeight: 300,
flexibleSpace: FlexibleSpaceBar(
background: Image.asset(
"assets/image/food.png",
width: double.maxFinite,
fit: BoxFit.cover,
),
),
)
],
),
);
}
}


try using SingleChildScrollView()

Related

Why is my SliverAppBar not responding at all?

I'm trying to implement a sliver app bar in my flutter app but it just won't respond at all
Widget build(BuildContext context) {
return const MaterialApp(
home: Scaffold(
body: CustomScrollView(
slivers: [
SliverAppBar(
expandedHeight: 200,
flexibleSpace: FlexibleSpaceBar(
title: Text("title"),
),
),
],
),
));
}
}

You need to add more slivers on CustomScrollView, when the viewport is bigger than slivers height, you will get the effect. Try adding SliverList or other sliver,
body: CustomScrollView(
slivers: [
SliverAppBar(
expandedHeight: 200,
flexibleSpace: FlexibleSpaceBar(
title: Text("title"),
),
),
SliverToBoxAdapter(
child: SizedBox(
height: 3333,
),
)
],
),
You can check this video

You can change it to this.
Widget build(BuildContext context) { return const MaterialApp( home: Scaffold( body: CustomScrollView(
slivers: [
SliverAppBar(
expandedHeight: 200,
flexibleSpace: FlexibleSpaceBar(
title: Text("title"),
),
expanded: true,
),
],
),
));
}}

Sliver appbar not stretching flutter

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(),
...
),

How to make Whatsapp like appbar in flutter

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,
),
),
],
),
);
}

How to scroll stacked containers with sticky header in Flutter?

I am trying to achieve scroll in Flutter Web where I have few containers which are stacked and I use SingleChildScrollView to scroll the widget. However, when I scroll the first container everything working fine but the second one which is a child of the second container responds to the scroll without completing the initial one. And also is there a way to make a sticky header for the second container. How can I make the 3rd container(orange) to scroll after the 2nd(blue) one is finished scrolling? Here is what I am trying to achieve:
https://yobithemes.com/demo/html/freda/dark-video-index.html
And here what I got so far:
class MainScreen extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Stack(
children: <Widget>[
IntroScreen(),
SingleChildScrollView(
child: Container(
child: Column(
children: <Widget>[
SizedBox(
height: MediaQuery.of(context).size.height - 100,
),
Container(
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.width,
color: Colors.blue,
child: SingleChildScrollView(
child: Column(
children: [
SizedBox(
height: MediaQuery.of(context).size.height,
),
Container(
padding: EdgeInsets.only(top: 100),
height: MediaQuery.of(context).size.height,
width: MediaQuery.of(context).size.width,
color: Colors.orange,
),
],
),
),
),
],
),
),
),
],
),
);
}
}

You can achieve it by using sliver.
SliverToBoxAdapter fill the transparent area with screen height - app bar height.
SliverAppBar: make it sticky by setting floating and pin to true
class MainScreen extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: Stack(
children: <Widget>[
IntroScreen(),
CustomScrollView(
slivers: [
SliverToBoxAdapter(
child: Container(
height: MediaQuery.of(context).size.height - 50,
),
),
SliverAppBar(
// toolbarHeight: 50,
floating: true,
pinned: true,
title: Container(
child: Center(child: Text('Header')),
),
),
SliverList(
delegate: SliverChildBuilderDelegate(
(context, index) => Container(
height: MediaQuery.of(context).size.height-50,
color: Colors.primaries[index % Colors.primaries.length],
),
),
),
],
),
],
),
);
}
}

How to stretch an image when user scrolls in flutter

I want to stretch an image when the user scrolls.
Container(
child: Image.asset(
'assets/appHeader.png',
fit: BoxFit.cover,
width: size.width,
height: 170,
),
)
This image is at the top of the page and when user scrolls up I want to stretch the image.
It will be like the stretch in SliverAppBar. I am pretty new to flutter so I don't know much about animation.

Try this, i am create this by using FlexibleSpaceBar.
#override
Widget build(BuildContext context) {
return Scaffold(
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
SliverAppBar(
expandedHeight: 200.0,
floating: false,
//pinned: true, if you need to show appBar.
pinned: false,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
title: Text("Image Text(optional)",
style: TextStyle(
color: Colors.white,
fontSize: 16.0,
)),
background: Image.network(
"https://miro.medium.com/max/700/1*_nCC_uFDVYas8uYa9m6fQQ.jpeg",
fit: BoxFit.cover,
)
/*-------Your Image here--------*/
/* Image.asset(
'assets/appHeader.png',
fit: BoxFit.cover,
width: size.width,
height: 170,
),*/
),
),
];
},
body: Center(
child: Text("Your screen data"),
),
),
);
}

this answer update regarding(that you ask in comment)(this applicable only for this situation that we discuss in question).
#override
Widget build(BuildContext context) {
return Container(
child: Stack(
children: [
Scaffold(
//same code that above write
)
],
),
);
}