Flutter draggable scrollable sheet - flutter

Question

does anyone know why my draggable scrollable sheet doesn't work or why I can't see it?
I tried it in another way it worked, but I didn't use the SafeArea-Widget,
import 'package:flutter/material.dart';
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: PreferredSize(
preferredSize: Size.fromHeight(100.0),
child: AppBar(
//AppBar
),
body: SafeArea(
child: ListView(
children: <Widget>[
Padding(
padding: EdgeInsets.only(left: 20),
child: Text(
dateday,
style: TextStyle(
color: Color(0xff2C8E5D),
fontSize: 150,
),
),
),
SizedBox.expand(
child: DraggableScrollableSheet(builder:
(BuildContext context, ScrollController scrollController) {
return Container(
color: Colors.red,
child: ListView.builder(
controller: scrollController,
itemCount: 25,
itemBuilder: (BuildContext context, int index) {
return ListTile(title: Text("Item $index"));
}),
);
}),
),
],
),
),
);
}
}
Thanks for your help!

Answer 1

Replace the ListView with a Stack:
body: SafeArea(
child: Stack(
children: <Widget>[
Padding(
padding: EdgeInsets.only(left: 20),
child: Text(
dateday,
style: TextStyle(
color: Color(0xff2C8E5D),
fontSize: 150,
),
),
),
SizedBox.expand(
child: DraggableScrollableSheet(
builder:
(BuildContext context, ScrollController scrollController) {
return Container(
color: Colors.red,
child: ListView.builder(
controller: scrollController,
itemCount: 25,
itemBuilder: (BuildContext context, int index) {
return ListTile(title: Text("Item $index"));
}),
);
}),
),
],
),
),

Answer 2

You can use LayoutBuilder and BoxConstraints to provide height and use Expanded flex to control DraggableScrollableSheet's scroll area
code snippet
SafeArea(
child: LayoutBuilder(builder: (context, constraints) {
return ConstrainedBox(
constraints: BoxConstraints(maxWidth: constraints.maxWidth),
child: Column(
children: <Widget>[
Expanded(
flex: 1,
child: Padding(
padding: EdgeInsets.only(left: 20),
child: Text(
"dateday",
...
Expanded(
flex: 3,
child: SizedBox.expand(
working demo
full code
import 'package:flutter/material.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
_counter++;
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: const Text('DraggableScrollableSheet'),
),
body: SafeArea(
child: LayoutBuilder(builder: (context, constraints) {
print(constraints.maxWidth);
print(constraints.minWidth);
return ConstrainedBox(
constraints: BoxConstraints(maxWidth: constraints.maxWidth),
child: Column(
children: <Widget>[
Expanded(
flex: 1,
child: Padding(
padding: EdgeInsets.only(left: 20),
child: Text(
"dateday",
style: TextStyle(
color: Color(0xff2C8E5D),
fontSize: 150,
),
),
),
),
Expanded(
flex: 3,
child: SizedBox.expand(
child: DraggableScrollableSheet(builder:
(BuildContext context,
ScrollController scrollController) {
return Container(
color: Colors.red,
child: ListView.builder(
controller: scrollController,
itemCount: 25,
itemBuilder: (BuildContext context, int index) {
return ListTile(title: Text("Item $index"));
}),
);
}),
),
),
],
),
);
}),
));
}
}