flutter圆角

有的时候我们需要给图片或者背景添加圆角,我们怎么做呢？
效果截图

flutter圆角

代码示例

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'flutter圆角'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Container(
          child: ListView(
        children: [
          ClipRRect(
            borderRadius: BorderRadius.only(
              topLeft: Radius.circular(20),
              bottomRight: Radius.circular(20),
            ),
            child: Image.asset("images/big.jpg"),
          ),
          Divider(
            height: 2,
          ),
          ClipRRect(
            borderRadius: BorderRadius.circular(20),
            child: Image.asset("images/big.jpg"),
          ),
          Divider(
            height: 2,
          ),
          Container(
            decoration: ShapeDecoration(
              image: DecorationImage(
                image: AssetImage("images/big.jpg"),
                fit: BoxFit.fitWidth,
              ),
              shape: RoundedRectangleBorder(
                  borderRadius: BorderRadiusDirectional.circular(20)),
            ),
            width: double.maxFinite,
            height: 300,
            child: Align(
              child: Padding(
                padding: const EdgeInsets.all(8.0),
                child: Text(
                  "Container decoration实现圆角(radius = 20)",
                  style: TextStyle(color: Colors.white),
                ),
              ),
              alignment: Alignment.bottomCenter,
            ),
          ),
          ClipRRect(
            borderRadius: BorderRadius.circular(20),
            child: Image.asset("images/big.jpg"),
          ),
          Card(
            shape: RoundedRectangleBorder(
              borderRadius: BorderRadiusDirectional.circular(20),
            ),
            clipBehavior: Clip.antiAlias,
            child: Image.asset(
              "images/big.jpg",
              width: double.maxFinite,
            ),
          ),
        ],
      )), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

1、灵活定义圆角。我们定义了左上角和右下角的圆角

          ClipRRect(
            borderRadius: BorderRadius.only(
              topLeft: Radius.circular(20),
              bottomRight: Radius.circular(20),
            ),
            child: Image.asset("images/big.jpg"),
          ),

2、四周弧度相同的圆角。

          ClipRRect(
            borderRadius: BorderRadius.circular(20),
            child: Image.asset("images/big.jpg"),
          ),

3、背景圆角弧度相同

          Container(
            decoration: ShapeDecoration(
              image: DecorationImage(
                image: AssetImage("images/big.jpg"),
                fit: BoxFit.fitWidth,
              ),
              shape: RoundedRectangleBorder(
                  borderRadius: BorderRadiusDirectional.circular(20)),
            ),
            width: double.maxFinite,
            height: 300,
            child: Align(
              child: Padding(
                padding: const EdgeInsets.all(8.0),
                child: Text(
                  "Container decoration实现圆角(radius = 20)",
                  style: TextStyle(color: Colors.white),
                ),
              ),
              alignment: Alignment.bottomCenter,
            ),
          ),

4、背景灵活定义四周圆角

          Container(
            decoration: ShapeDecoration(
              image: DecorationImage(
                image: AssetImage("images/big.jpg"),
                fit: BoxFit.fitWidth,
              ),
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadiusDirectional.only(
                  topStart: Radius.circular(20),
                  bottomEnd: Radius.circular(20),
                ),
              ),
            ),
            width: double.maxFinite,
            height: 300,
            child: Align(
              child: Padding(
                padding: const EdgeInsets.all(8.0),
                child: Text(
                  "Container decoration实现圆角(radius = 20)",
                  style: TextStyle(color: Colors.white),
                ),
              ),
              alignment: Alignment.bottomCenter,
            ),
          ),

5、card圆角

          Card(
            shape: RoundedRectangleBorder(
              borderRadius: BorderRadiusDirectional.circular(20),
            ),
            clipBehavior: Clip.antiAlias,
            child: Image.asset(
              "images/big.jpg",
              width: double.maxFinite,
            ),
          ),