如何在 flutter 的容器中创建曲线

Question

How to create curve in container like this

Answer 1

If you need to create a curve for the container that the profile picture lives on top of, your best bet would be to use a ClipPath with a custom clipper.

Something like this would do the trick:

ClipPath(
  clipper: CurveClipper(),
  child: Container(
    color: Colors.red,
    height: 200.0,
  ),
);

Our custom CurveClipper requires us to draw a path that includes a bézier curve, to get that curve shape at the bottom of our container:

class CurveClipper extends CustomClipper<Path> {
  @override
  Path getClip(Size size) {
    int curveHeight = 40;
    Offset controlPoint = Offset(size.width / 2, size.height + curveHeight);
    Offset endPoint = Offset(size.width, size.height - curveHeight);

    Path path = Path()
      ..lineTo(0, size.height - curveHeight)
      ..quadraticBezierTo(controlPoint.dx, controlPoint.dy, endPoint.dx, endPoint.dy)
      ..lineTo(size.width, 0)
      ..close();

    return path;
  }

  @override
  bool shouldReclip(CustomClipper<Path> oldClipper) => false;
}

Answer 2

It's rounded Appbar actually in this picture. To achive this:

AppBar(
    title: Text('Anything'),
    shape: RoundedRectangleBorder(
      borderRadius: BorderRadius.vertical(
        bottom: Radius.circular(30),
      ),
    ),
  ),

If you want container with this shape:

Container(
    height: 200.0,
    decoration: new BoxDecoration(
      color: Colors.red,
      borderRadius: BorderRadius.vertical(
          bottom: Radius.elliptical(
              MediaQuery.of(context).size.width, 100.0)),
    ),
  ),

Answer 3

I used CustomPainter to draw the required container and placed it at the bottom of the stack. The rest of the widgets can be aligned on top as required. Complete the rest of the screen by populating the Column widget.

Image of the output is as shown: Output Image for the design

Code

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: ProfileScreen(),
    );
  }
}

// class to draw the profile screen
class ProfileScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: Scaffold(
        appBar: AppBar(
          elevation: 0.0,
          backgroundColor: const Color(0xffea5d49),
          leading: Icon(
            Icons.menu,
            color: Colors.white,
          ),
        ),
        body: Stack(
          alignment: Alignment.center,
          children: [
            CustomPaint(
              child: Container(
                width: MediaQuery.of(context).size.width,
                height: MediaQuery.of(context).size.height,
              ),
              painter: HeaderCurvedContainer(),
            ),
            Column(
              crossAxisAlignment: CrossAxisAlignment.center,
              children: [
                Padding(
                  padding: const EdgeInsets.all(20.0),
                  child: Text(
                    'Profile',
                    style: TextStyle(
                      fontSize: 35.0,
                      letterSpacing: 1.5,
                      color: Colors.white,
                      fontWeight: FontWeight.w600,

                    ),
                  ),
                ),
                Container(
                  width: MediaQuery.of(context).size.width / 2,
                  height: MediaQuery.of(context).size.width / 2,
                  padding: const EdgeInsets.all(10.0),
                  decoration: BoxDecoration(
                    shape: BoxShape.circle,
                    color: Colors.white,
                    // image: DecorationImage(
                    //   image: AssetImage(null),
                    //   fit: BoxFit.cover,
                    // ),
                  ),
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

// CustomPainter class to for the header curved-container
class HeaderCurvedContainer extends CustomPainter {
  @override
  void paint(Canvas canvas, Size size) {
    Paint paint = Paint()..color = const Color(0xffea5d49);
    Path path = Path()
      ..relativeLineTo(0, 150)
      ..quadraticBezierTo(size.width / 2, 250.0, size.width, 150)
      ..relativeLineTo(0, -150)
      ..close();

    canvas.drawPath(path, paint);
  }

  @override
  bool shouldRepaint(CustomPainter oldDelegate) => false;
}

Answer 4

How to create curve in container like this