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Flutter开发:Gridview的使用详解

  Gridview常用的几种方式

  1、GridView.count(@required int crossAxisCount)

  GridView.count的使用,需要传的是int类型的参数,也就是创建固定数量的item,crossAxisCount表示横轴item的个数(系统默认是横轴);

  2、GridView.extent(@required double maxCrossAxisExtent)

  GridView.extent的使用,需要传的是double类型的参数,也就是创建横轴上最大可容纳的item,maxCrossAxisExtent表示横轴item的最大宽度;郑州看妇科医院去哪好http://www.tongjink.com/

  3、GridView.builder(@required this.gridDelegate,@required IndexedWidgetBuilder itemBuilder)

  适用于widget数量多的时候,通过GridView.builder的使用,动态的创建widget,itemBuilder表示子widget构造器;

  4、GridView.custom(@required this.gridDelegate,@required this.childrenDelegate)

  GridView.custom的使用,通过两个代理方法gridDelegate和childrenDelegate来创建Gridview,其中gridDelegate是进行布局的代理,控制每列或每行的子widget的数量,以及上下左右间距和宽高比例;childrenDelegate的代理方法有两种实现方式,在使用的时候需要注意二者的区别。

  Gridview的简单使用的实例,具体操作如下所示:

  1、dart文件的具体实现源码

  import 'package:flutter/material.dart';

  import 'package:portal/model/workspace_item_data.dart';

  import 'package:portal/widgets/widget_warpper.dart';

  class WorkspacePage extends StatefulWidget {

  @override

  _WorkspacePageState createState() => _WorkspacePageState();

  }

  class _WorkspacePageState extends State {

  Widget build(BuildContext context) {

  return Scaffold(

  appBar: buildAppBar(context, title: "工作台", leading: Container()),

  body: GridView.builder(

  itemCount: listData.length,

  gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(

  crossAxisCount: 3, mainAxisSpacing: 10, crossAxisSpacing: 10, childAspectRatio: 0.9),

  padding: EdgeInsets.all(10),

  itemBuilder: getItem,

  ),

  );

  Widget getItem(context, index) {

  return Container(

  decoration:

  BoxDecoration(border: Border.all(color: Colors.black12, width: 2)),

  child: Column(

  children: [

  Image.network(listData[index]['imageUrl']),

  SizedBox(

  height: 10,

  Text(listData[index]['title'])

  ],

  2、数据源文件

  Gridview的itemCount的数据源(为了体现列表效果,刻意多造了几条数据):

  List listData=[

  {

  "title": '行政审批',

  "author": 'Mohamed Chahin',

  "imageUrl": 'https://www.itying.com/images/flutter/1.png',

  },

  "title": '协同办公',

  "author": 'Google',

  "imageUrl": 'https://www.itying.com/images/flutter/2.png',

  "title": '实名认证',

  "author": 'Alibaba',

  "imageUrl": 'https://www.itying.com/images/flutter/3.png',

  "title": '会议室',

  "imageUrl": 'https://www.itying.com/images/flutter/4.png',

  "title": '企业邮箱',

  "imageUrl": 'https://www.itying.com/images/flutter/5.png',

  "title": '测温',

  "imageUrl": 'https://www.itying.com/images/flutter/6.png',

  "title": '企业文化',

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