如何在 flutter 中定义 Custom BorderRadius class?
How to define Custom BorderRadius class in flutter?
标准化设计,避免错误并减少构建时间,
我正在尝试定义一个 BorderRadius class,它将 double corner
值作为参数,因此它可以在整个应用程序的许多地方使用
我在定义 class 构造函数时遇到很多错误,无法在此处真正找到解决方案
import 'package:flutter/material.dart';
class Borderz extends BorderRadius{
final BorderRadius enBorderz;
final double corner;
static const double zeroCorner = 0.0,
const Borderz({
@required this.corner,
this.enBorderz = BorderRadius.only(
topLeft: Radius.circular(corner),
topRight: Radius.circular(corner),
bottomLeft: Radius.circular(corner),
bottomRight: Radius.circular(zeroCorner),
)
}) : super(zeroCorner : zeroCorner)
}
此代码中存在一些严重的基本错误,让我感到尴尬,感谢您的帮助
您可以复制粘贴 运行 下面的完整代码
可以直接调用super.only
,不需要使用enBorderz
class Borderz extends BorderRadius {
final double corner;
static const double zeroCorner = 0.0;
Borderz({
@required this.corner,
}) : super.only(
topLeft: Radius.circular(corner),
topRight: Radius.circular(corner),
bottomLeft: Radius.circular(corner),
bottomRight: Radius.circular(zeroCorner),
);
}
...
Container(
width: 100,
height: 100,
child: Center(
child: Text(
'test',
),
),
decoration: BoxDecoration(
borderRadius: Borderz(corner: 10.0),
color: Colors.blue,
),
),
工作演示
完整代码
import 'package:flutter/material.dart';
class Borderz extends BorderRadius {
final double corner;
static const double zeroCorner = 0.0;
Borderz({
@required this.corner,
}) : super.only(
topLeft: Radius.circular(corner),
topRight: Radius.circular(corner),
bottomLeft: Radius.circular(corner),
bottomRight: Radius.circular(zeroCorner),
);
}
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: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Container(
width: 100,
height: 100,
child: Center(
child: Text(
'test',
),
),
decoration: BoxDecoration(
borderRadius: Borderz(corner: 10.0),
color: Colors.blue,
),
),
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}
标准化设计,避免错误并减少构建时间,
我正在尝试定义一个 BorderRadius class,它将 double corner
值作为参数,因此它可以在整个应用程序的许多地方使用
我在定义 class 构造函数时遇到很多错误,无法在此处真正找到解决方案
import 'package:flutter/material.dart';
class Borderz extends BorderRadius{
final BorderRadius enBorderz;
final double corner;
static const double zeroCorner = 0.0,
const Borderz({
@required this.corner,
this.enBorderz = BorderRadius.only(
topLeft: Radius.circular(corner),
topRight: Radius.circular(corner),
bottomLeft: Radius.circular(corner),
bottomRight: Radius.circular(zeroCorner),
)
}) : super(zeroCorner : zeroCorner)
}
此代码中存在一些严重的基本错误,让我感到尴尬,感谢您的帮助
您可以复制粘贴 运行 下面的完整代码
可以直接调用super.only
,不需要使用enBorderz
class Borderz extends BorderRadius {
final double corner;
static const double zeroCorner = 0.0;
Borderz({
@required this.corner,
}) : super.only(
topLeft: Radius.circular(corner),
topRight: Radius.circular(corner),
bottomLeft: Radius.circular(corner),
bottomRight: Radius.circular(zeroCorner),
);
}
...
Container(
width: 100,
height: 100,
child: Center(
child: Text(
'test',
),
),
decoration: BoxDecoration(
borderRadius: Borderz(corner: 10.0),
color: Colors.blue,
),
),
工作演示
完整代码
import 'package:flutter/material.dart';
class Borderz extends BorderRadius {
final double corner;
static const double zeroCorner = 0.0;
Borderz({
@required this.corner,
}) : super.only(
topLeft: Radius.circular(corner),
topRight: Radius.circular(corner),
bottomLeft: Radius.circular(corner),
bottomRight: Radius.circular(zeroCorner),
);
}
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: Text(widget.title),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Container(
width: 100,
height: 100,
child: Center(
child: Text(
'test',
),
),
decoration: BoxDecoration(
borderRadius: Borderz(corner: 10.0),
color: Colors.blue,
),
),
Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: Icon(Icons.add),
),
);
}
}