flutter控件之GridView

import 'package:flutter/material.dart';
class LearnGridView extends StatefulWidget{
  @override
  State<StatefulWidget> createState() {
    return _LearnGridView();
  }
}
class _LearnGridView extends State<StatefulWidget>{
  @override
  Widget build(BuildContext context) {
    return new Scaffold(
     body: new GridView.builder(
         gridDelegate: new SliverGridDelegateWithMaxCrossAxisExtent(//SliverGridDelegateWithFixedCrossAxisCount可以直接指定每行（列）显示多少个Item   SliverGridDelegateWithMaxCrossAxisExtent会根据GridView的宽度和你设置的每个的宽度来自动计算没行显示多少个Item
           crossAxisSpacing:10.0,
           mainAxisSpacing: 10.0,
           maxCrossAxisExtent: 100.0,
         ),
         itemBuilder:  (BuildContext context, int index) {
           return new Image.network(
             'https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=15335368'
                 '41326&di=682e2e7c3810ac92be325e62e173c0ea&imgtype=0&src=http%3A%2F%2Fs6.si'
                 'naimg.cn%2Fmw690%2F006LDoUHzy7auXEaYER25%26690',
             fit: BoxFit.cover,
           );
         },
       itemCount: 100,
     ),
    );
  }
}