Paddiing 组件

一、Flutter Paddiing 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。

 

属性	说明
padding	padding 值, EdgeInsetss 设置填充的值
child	子组件

 

class LayoutDemo extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: EdgeInsets.fromLTRB(0, 0, 10, 0),
      child: GridView.count(
        crossAxisCount: 2,
        childAspectRatio: 1.5,
        children: <Widget>[
          Padding(
            padding: EdgeInsets.fromLTRB(10, 10, 0, 0),
            child: Image.network('https://www.itying.com/images/flutter/1.png',
                fit: BoxFit.cover),
          ),
          Padding(
            padding: EdgeInsets.fromLTRB(10, 10, 0, 0),
            child: Image.network('https://www.itying.com/images/flutter/2.png',
                fit: BoxFit.cover),
          ),
          Padding(
            padding: EdgeInsets.fromLTRB(10, 10, 0, 0),
            child: Image.network('https://www.itying.com/images/flutter/3.png',
                fit: BoxFit.cover),
          ),
          Padding(
            padding: EdgeInsets.fromLTRB(10, 10, 0, 0),
            child: Image.network('https://www.itying.com/images/flutter/4.png',
                fit: BoxFit.cover),
          ),
          Padding(
            padding: EdgeInsets.fromLTRB(10, 10, 0, 0),
            child: Image.network('https://www.itying.com/images/flutter/5.png',
                fit: BoxFit.cover),
          ),
          Padding(
            padding: EdgeInsets.fromLTRB(10, 10, 0, 0),
            child: Image.network('https://www.itying.com/images/flutter/6.png',
                fit: BoxFit.cover),
          ),
        ],
      ),
    );
  }
}

二、Flutter Row 水平布局组件

属性	说明
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: 700,
      width: 500,
      color: Colors.black26,
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.center,
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        // crossAxisAlignment: CrossAxisAlignment.center,
        children: <Widget>[
          IconContainer(Icons.home, color: Colors.red),
          IconContainer(Icons.search, color: Colors.blue),
          IconContainer(Icons.send, color: Colors.orange),
        ],
      ),
    );
  }
}

class IconContainer extends StatelessWidget {
  double size;
  IconData icon;
  Color color;

  IconContainer(this.icon, {this.size, this.color = Colors.blue}) {
    this.size = 32.0;
  }

  @override Widget build(BuildContext context) {
    return Container(
        width: this.size+60,
        height: this.size+60,
        color:this.color,
        child: Center(
            child: Icon(this.icon,color:Colors.white,size:this.size)
        )
    );
  }

}