10Flutter页面布局 Padding Row Column Expanded组件详解：

Padding组件：

main.dart

import 'package:flutter/material.dart';
import 'res/listData.dart';
/*
  flutter页面布局Padding Row Column Expanded组件详情：
*/

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Padding Row Column Expanded'),
        ),
        body: HomeContent(),
      ),
    );
  }
}

class HomeContent 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://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/1.png",
                fit: BoxFit.cover),
          ),
          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/1.png",
                fit: BoxFit.cover),
          ),
          Padding(
            padding: EdgeInsets.fromLTRB(10, 10, 0, 0),
            child: Image.network("https://www.itying.com/images/flutter/1.png",
                fit: BoxFit.cover),
          )
        ],
      ),
    );
  }
}

Row水平布局组件：

import 'package:flutter/material.dart';
import 'res/listData.dart';
/*
  flutter页面布局Padding Row Column Expanded组件详情：
  Row水平布局组件：
  mainAxisAlignment 主轴的排序方式
  crossAxisAlignment 次轴的排序方式
  children 组件子元素：
*/

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Padding Row Column Expanded'),
        ),
        body: HomeContent(),
      ),
    );
  }
}

class HomeContent extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      height: 800.0,
       400.0,
      color: Colors.pink,
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          IconContainer(Icons.home, color: Colors.blue),
          IconContainer(Icons.search, 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,
       100.0,
      color: this.color,
      child: Center(
        child: Icon(this.icon, size: this.size, color: Colors.white),
      ),
    );
  }
}

Column 垂直布局：

import 'package:flutter/material.dart';
import 'res/listData.dart';
/*
  flutter页面布局Padding Row Column Expanded组件详情：
  Column水平布局组件：
  mainAxisAlignment 主轴的排序方式
  crossAxisAlignment 次轴的排序方式
  children 组件子元素：
*/

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Padding Row Column Expanded'),
        ),
        body: HomeContent(),
      ),
    );
  }
}

class HomeContent extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Container(
      height: 800.0,
       400.0,
      color: Colors.pink,
      child: Column(
        mainAxisAlignment: MainAxisAlignment.spaceEvenly,
        crossAxisAlignment: CrossAxisAlignment.start,
        children: <Widget>[
          IconContainer(Icons.home, color: Colors.blue),
          IconContainer(Icons.search, 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,
       100.0,
      color: this.color,
      child: Center(
        child: Icon(this.icon, size: this.size, color: Colors.white),
      ),
    );
  }
}

Expanded

import 'package:flutter/material.dart';
import 'res/listData.dart';
/*
  Flutter Expanded类似Web中的Flex布局：
  flex:元素占整个父Row/Column的比例：
  child 子元素

*/

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('Padding Row Column Expanded'),
        ),
        body: HomeContent(),
      ),
    );
  }
}

class HomeContent 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),
        // )

        Expanded(
          flex: 1,
          child: IconContainer(Icons.home,color:Colors.orange),
        ),
        IconContainer(Icons.search,color:Colors.blue)
      ],
    );
  }
}

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,
       100.0,
      color: this.color,
      child: Center(
        child: Icon(this.icon, size: this.size, color: Colors.white),
      ),
    );
  }
}