How to make curved bottom appBar in Flutter? - flutter

Question

How to draw custom shape for the appBar in my application to look like the image?

Answer 1

I think it is not the appBar's shape.
I think it's the white container below the green-colored appBar that has the rounded corner.
Here's the example:
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.lightBlueAccent,
body: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Container(
padding: EdgeInsets.only(
top: 60.0, left: 30.0, right: 30.0, bottom: 30.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Text(
'Hello',
style: TextStyle(
color: Colors.white,
fontSize: 50.0,
fontWeight: FontWeight.w700,
),
),
],
),
),
Expanded(
child: Container(
padding: EdgeInsets.symmetric(horizontal: 20.0),
decoration: BoxDecoration(
color: Colors.white,
borderRadius: BorderRadius.only(
topLeft: Radius.circular(20.0),
topRight: Radius.circular(20.0),
),
),
),
),
],
),
);
}
}

Answer 2

I built something similar with a CustomScrollView and SliverPersistenHeader, to get the curved effect your header can have a maxExtent and minExtent. When not scrolled the header height will show the curve otherwise when you start scrolling it will also shrink to a set height.
You can check out this tutorial from around 2:50 to get an idea of how to implement the header and then design your background containers accordingly.

Answer 3

As answer above. It is not part of the appbar programatically. Here is how I do it.
Create a class as such:
import 'dart:ui';
import 'package:flutter/material.dart';
class AppBarPainter extends CustomPainter {
#override
void paint(Canvas canvas, Size size) {
Paint paint_1 = Paint()
..color = const Color(0xffF57752)
..style = PaintingStyle.fill;
Path path_1 = Path()
..moveTo(0, 0)
..lineTo(size.width * .08, 0.0)
..cubicTo(
size.width * 0.04, 0.0, //x1,y1
0.0, 0.04, //x2,y2
0.0, 0.1 * size.width //x3,y3
);
Path path_2 = Path()
..moveTo(size.width, 0)
..lineTo(size.width * .92, 0.0)
..cubicTo(
size.width * .96, 0.0, //x1,y1
size.width, 0.96, //x2,y2
size.width, 0.1 * size.width //x3,y3
);
Paint paint_2 = Paint()
..color = const Color(0xffF57752)
..strokeWidth = 1
..style = PaintingStyle.stroke;
Path path_3 = Path()
..moveTo(0, 0)
..lineTo(size.width, 0);
canvas.drawPath(path_1, paint_1);
canvas.drawPath(path_2, paint_1);
canvas.drawPath(path_3, paint_2);
}
And then use it in your screen by stacking it ontop of body widget.
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
toolbarHeight: 80.0,
backgroundColor: const Color(0xffF57752),
elevation: 0.0,
title: const Text('Title'),
),
body: Stack(
children: [
Container(
color: Colors.white,
child: Text(' text here'),
),
CustomPaint(
painter: AppBarPainter(),
child: Container(height: 0),
),
],
),
);
}