Flutter学习之GridView

方案1

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget{
  @override
  Widget build(BuildContext context ){
      return MaterialApp(
        title:'ListView widget',
        home:Scaffold(
          appBar: new AppBar(
            title: new Text("网格视图"),
          ),
          body:GridView.count(
            padding:const EdgeInsets.all(2.0),
            childAspectRatio: 0.7,		//图片的长宽比
            mainAxisSpacing: 2.0,		//每一行间距
            crossAxisSpacing: 2.0,		//每一列间距
            crossAxisCount: 2,			//每一行的列数
            children: <Widget>[
              new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            ],
          )
        ),
      );
  }
}

方案2

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget{
  @override
  Widget build(BuildContext context){
    return MaterialApp(
      title: "grid view",
      home: Scaffold(
        appBar: new AppBar(
          title: new Text("grid view"),
          backgroundColor: Colors.pinkAccent,
        ),
        body: GridView(
          gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
            crossAxisCount: 2,            //每行的列数
            mainAxisSpacing: 2.0,       //纵向间距
            crossAxisSpacing: 2.0,    //横向间距
            childAspectRatio: 0.71,  //缩放比例 ，图片的长宽比
          ),
          children: <Widget>[
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),            
          ]

        )
        ),
      );
  }
}

平时我们看到的手机相册，淘宝商品列表其实就是网格视图的应用
Flutter里也有网格组件GridView

GridView.count(
            padding:const EdgeInsets.all(2.0),
            childAspectRatio: 0.7,
            mainAxisSpacing: 2.0,
            crossAxisSpacing: 2.0,
            crossAxisCount: 2,
            children: <Widget>[
            new Image.network("http://img5.mtime.cn/mg/2019/01/25/105551.72978167_126X190X4.jpg",fit: BoxFit.cover),
             ],
          )

上面的代码是比较常用的方法
使用GridView.count的接口
在里面使用

• padding: const EdgeInsets.all(2.0)(距离边框的距离)
• childAspectRatio: 0.7 （子组件的长宽比为1：0.7）
• mainAxisSpacing：2.0 （纵向间距）
• crossAxisSpacing: 2,0 （横向间距）
• crossAxisCount: 2 (每行有两个子组件)

下面是示例图