flutter页面布局一
2024-09-06 04:31:11
Padding组件
在 html 中常见的布局标签都有 padding 属性,但是 Flutter 中很多 Widget 是没有 padding 属性。这个时候我们可以用 Padding 组件处理容器与子元素直接的间距。
该组件接收两个属性:
- padding :padding 值, EdgeInsetss 设置填充的值
- child :子组件
例如,要实现前面的网格布局里面的单元格之间的间距,就可以使用Padding组件。
import 'package:flutter/material.dart'; void main() => runApp(MyApp()); class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
// TODO: implement build
return MaterialApp(
home: Scaffold(
appBar: AppBar(title: Text('FlutterDemo')),
body: LayoutDemo(),
));
}
} class LayoutDemo extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Padding(
padding: EdgeInsets.fromLTRB(0, 0, 10, 0),
child: GridView.count(
crossAxisCount: 2,
childAspectRatio: 1.7,
children: <Widget>[
Padding(
padding: EdgeInsets.fromLTRB(10, 10, 0, 0),
child: Image.network('https://img.ivsky.com/img/tupian/li/201810/30/motianlun-005.jpg',
fit: BoxFit.cover),
),
Padding(
padding: EdgeInsets.fromLTRB(10, 10, 0, 0),
child: Image.network('https://img.ivsky.com/img/tupian/li/201811/06/xiaosongshu-002.jpg',
fit: BoxFit.cover),
),
Padding(
padding: EdgeInsets.fromLTRB(10, 10, 0, 0),
child: Image.network('https://img.ivsky.com/img/tupian/li/201811/06/ludeng-006.jpg',
fit: BoxFit.cover),
),
Padding(
padding: EdgeInsets.fromLTRB(10, 10, 0, 0),
child: Image.network('https://img.ivsky.com/img/tupian/li/201811/06/seattle-005.jpg',
fit: BoxFit.cover),
),
Padding(
padding: EdgeInsets.fromLTRB(10, 10, 0, 0),
child: Image.network('https://img.ivsky.com/img/tupian/li/201811/07/osaka-005.jpg',
fit: BoxFit.cover),
),
Padding(
padding: EdgeInsets.fromLTRB(10, 10, 0, 0),
child: Image.network('https://img.ivsky.com/img/tupian/li/201811/07/mushroom.jpg',
fit: BoxFit.cover),
),
],
));
}
}
Row 水平布局组件
Row组件用于实现水平布局,相比于ListView的水平排列而言,这个Row的宽度是可控的,二者之间的参数也是不一样的,Row组件技术的参数为:
- mainAxisAlignment :主轴的排序方式
- crossAxisAlignment:次轴的排序方式
- children:组件子元素
import 'package:flutter/material.dart'; void main() => runApp(MyApp()); class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(title: Text('FlutterDemo')),
body: LayoutDemo(),
));
}
} class LayoutDemo extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Container(
height: 800.0,
width: 400.0,
color: Colors.pink,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
IconContainer(Icons.search,color: Colors.blue),
IconContainer(Icons.home,color: Colors.orange),
IconContainer(Icons.select_all,color: Colors.red),
],
),
);
}
} class IconContainer extends StatelessWidget{
double size=32.0;
Color color=Colors.red;
IconData icon;
IconContainer(this.icon,{this.color,this.size});
@override
Widget build(BuildContext context) {
// TODO: implement build
return Container(
height: 100.0,
width: 100.0,
color: this.color,
child: Center(
child: Icon(this.icon,size: this.size,color: Colors.white)
),
);
}
}
Column 垂直布局组件
Column组件是区别于Row组件的,用于实现垂直布局,接收的参数和上面的Row是一样的。
class LayoutDemo extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Container(
height: 800.0,
width: 400.0,
color: Colors.pink,
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
crossAxisAlignment: CrossAxisAlignment.end,
children: <Widget>[
IconContainer(Icons.search,color: Colors.blue),
IconContainer(Icons.home,color: Colors.orange),
IconContainer(Icons.select_all,color: Colors.red),
],
),
);
}
}
Expanded组件
Expanded 可以用在 Row 和 Column 布局中 ,用于实现类似web中的Flex布局。
import 'package:flutter/material.dart'; void main() => runApp(MyApp()); class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
// TODO: implement build
return MaterialApp(
home: Scaffold(
appBar: AppBar(title: Text('FlutterDemo')),
body: LayoutDemo(),
));
}
} class LayoutDemo extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Row( children: <Widget>[
Expanded(
flex: 1,
child: IconContainer(Icons.search,color: Colors.blue)
),
Expanded(
flex: 2,
child: IconContainer(Icons.home,color: Colors.orange),
),
Expanded(
flex: 1,
child: IconContainer(Icons.select_all,color: Colors.red),
), ],
);
}
} class IconContainer extends StatelessWidget{
double size=32.0;
Color color=Colors.red;
IconData icon;
IconContainer(this.icon,{this.color,this.size});
@override
Widget build(BuildContext context) {
// TODO: implement build
return Container(
height: 100.0,
width: 100.0,
color: this.color,
child: Center(
child: Icon(this.icon,size: this.size,color: Colors.white)
),
);
}
}
上面是实现等分的,既然是类似于Flex的,那么,也可以实现部分固定宽度,剩余部分自适应的效果:
class LayoutDemo extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Row(
children: <Widget>[
Expanded(
flex: 1,
child: IconContainer(Icons.home,color: Colors.orange),
),
IconContainer(Icons.search,color: Colors.blue)
],
);
}
}
最后,我们就可以结合上面的知识,实现下面的布局了:
import 'package:flutter/material.dart'; void main() => runApp(MyApp()); class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
// TODO: implement build
return MaterialApp(
home: Scaffold(
appBar: AppBar(title: Text('FlutterDemo')),
body: LayoutDemo(),
));
}
} class LayoutDemo extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Column(
children: <Widget>[ Row(
children: <Widget>[
Expanded(
child: Container(
height: 180,
color: Colors.black,
child: Text('你好Flutter'),
),
)
],
),
SizedBox(height: 10),
Row(
children: <Widget>[
Expanded(
flex: 2,
child: Container(
height: 180,
child: Image.network("https://ss3.bdstatic.com/70cFv8Sh_Q1YnxGkpoWK1HF6hhy/it/u=2606512668,2361120991&fm=27&gp=0.jpg",fit: BoxFit.cover),
)
),
SizedBox(width: 10),
Expanded(
flex: 1,
child: Container(
height: 180,
child: ListView(
children: <Widget>[
Container(
height: 85,
child: Image.network("https://ss3.bdstatic.com/70cFv8Sh_Q1YnxGkpoWK1HF6hhy/it/u=2606512668,2361120991&fm=27&gp=0.jpg",fit: BoxFit.cover),
),
SizedBox(height: 10),
Container(
height: 85,
child: Image.network("https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=2191520521,2689315141&fm=27&gp=0.jpg",fit: BoxFit.cover),
)
],
)
)
), ],
)
],
);
}
}
最新文章
- AngularJS学习第一课
- 在wex5平台grid显示问题
- 4、CC2541芯片中级教程-OSAL操作系统(简单AT指令实现+IIC软件和硬件实现驱动MPU6050)
- oop第二章1知识点汇总
- Requirements of an SAP system administrator
- linux命令(8)kill命令
- 基于jquery打造的网页右侧自动收缩浮动在线客服代码
- 谈一下spring 的理解
- winform —— listview创建表及简单的增删改查
- zoj 3829 Known Notation(2014在牡丹江区域赛k称号)
- 使用solr6.0搭建solrCloud
- MATLAB R2017a 安装与破解
- Redis- 简单操作命令
- jmeter执行case结果插入DB生成报表和备份记录
- Process 开启子进程 的两种方式、join控制子进程、守护进程
- Sublime Text3—系统设置
- Mac android studio 一直卡在Gradle:Build Running的解决办法
- javascript parseUrl函数(来自国外的获取网址url参数)
- 1. SpringBoot启动后,报异常:This application has no explicit mapping for /error, so you are seeing this as a fallback.
- http://www.bugku.com:Bugku——变量1(http://120.24.86.145:8004/index1.php)