利用Flutter写一个跨平台的果核APP(2)——界面篇2

前言

紧接上篇文章《利用Flutter写一个跨平台的果核APP(1)——界面篇1》 上篇文章只是将界面的基本框架搭了出来,这篇文章着手实现首页的界面。先来看预览图: android

Screenshot_2018-09-14-18-48-09-649_com.lyy.guohe.png
这是此次实现的结果图:

解析

按照图像的分割线,我将整个首页分割成头部、今日课表部分、消息部分和日知录部分跨域

  1. 首先是首页的最外层框架部分
@override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new Scaffold(
        appBar: new AppBar(
          leading: new IconButton(
            icon: Icon(Icons.home),
            onPressed: () {
              //打开drawer
              openDrawer();
            },
          ),
          title: new Text("今日"), //设置标题内容
          backgroundColor: Color.fromARGB(255, 119, 136, 213), //设置appbar背景颜色
          centerTitle: true, //设置标题是否局中
        ),
        body: new ListView(
          children: <Widget>[
            new Header(),     //头部
            new BigDivider(),
            new TodayKb(),    //今日课表
            new BigDivider(),
            new Message(),    //消息
            new BigDivider(),
            new One()         //日知录
          ],
        ),
      ),
    );
  }
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由于首页布局较长,因此我选择用了一个ListView将一些控件包裹住,这里的ListView的做用就和android中的Scrollview的做用是同样的。BigDivider类是为了弥补Divider类空闲过小的不足自定义的一个view,我将这个view写在views/customview.dart里面了,因此须要在开头引入bash

import 'package:flutter_guohe/views/customview.dart';
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customview.dart中的BigDivider类app

import 'package:flutter/material.dart';

//分隔栏
class BigDivider extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new SizedBox(
      height: 5.0,
      child: new Center(
        child: new Container(
          height: 5.0,
          color: Colors.black12,
        ),
      ),
    );
  }
}
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剩下的就是依次实现上述的几个类,熟练使用Padding/Column/Row/Container等布局便可,在这里有3个点须要提一下:框架

  1. 图片资源的引用
  2. 均分布局的实现
  3. 利用EventBus实现子控件控制父控件

对于第一个,其实官方文档里有介绍《资源与图像》,可是文档里写的并无说明assets文件夹存放的路径,在这里说明一下,assets文件夹是和lib文件夹同级的,即less

assets文件夹存放的路径
若是想要引用assets文件夹中的路径,须要先在 pubspec.yaml文件中添加资源文件的依赖,以下所示:
添加依赖
使用的话只须要执行

new AssetImage('assets/imgs/ic_menu_score.png'),
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代码便可引用该资源文件。ide

第二个 布局

头部图标均分
这里很明显是一个Row里面包含5个Column布局,并且这5个Column是均分整个Row的,怎么实现均分了,用一个Expanded()包住一个Column,而后设置其flex为1便可,这个属性就相似安卓里面的 layout_weight,这样的话理解起来就不难了

第三个的使用场景是这样的: flex

AppBar左上角有一个IconButton,点击该IconButton弹出Drawer,可是因为该AppBar和Drawer并非处在同一个页面中(AppBar在today.dart文件,Drawer在app.dart文件里),因此如何跨域调用这个openDrawer()这个方法便成为了一个难题,这里推荐使用 EventBus方式,具体如何操做推荐阅读 《flutter基础-组件通讯(父子、兄弟)》,在这种状况下 DrawerIconButton属于兄弟组件。

完整代码

today.dartui

import 'package:flutter/material.dart';
import 'package:flutter_guohe/common/eventBus.dart';
import 'package:flutter_guohe/views/customview.dart';

class Today extends StatefulWidget {
  @override
  TodayState createState() => new TodayState();
}

class TodayState extends State<Today> {
  //打开drawer
  void openDrawer() {
    eventBus.fire(new EventOpenDrawer(true));
  }

  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new Scaffold(
        appBar: new AppBar(
          leading: new IconButton(
            icon: Icon(Icons.home),
            onPressed: () {
              //打开drawer
              openDrawer();
            },
          ),
          title: new Text("今日"), //设置标题内容
          backgroundColor: Color.fromARGB(255, 119, 136, 213), //设置appbar背景颜色
          centerTitle: true, //设置标题是否局中
        ),
        body: new ListView(
          children: <Widget>[
            new Header(),     //头部
            new BigDivider(),
            new TodayKb(),    //今日课表
            new BigDivider(),
            new Message(),    //消息
            new BigDivider(),
            new One()         //日知录
          ],
        ),
      ),
    );
  }
}

//首页的头部信息
class Header extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Container(
      height: 100.0,
      margin: new EdgeInsets.all(8.0),
      child: new Row(
        children: <Widget>[
          new Expanded(
            child: new Column(
              children: <Widget>[
                //头像
                new Container(
                  width: 60.0,
                  height: 60.0,
                  margin: new EdgeInsets.all(8.0),
                  decoration: BoxDecoration(
                    image: DecorationImage(
                      image: new AssetImage('assets/imgs/ic_menu_score.png'),
                      //从Assets加载图片
                      fit: BoxFit.cover,
                    ),
                    shape: BoxShape.circle,
                  ),
                ),
                new Text(
                  '查成绩',
                  textAlign: TextAlign.center,
                )
              ],
            ),
            flex: 1,
          ),
          new Expanded(
            child: new Column(
              children: <Widget>[
                //头像
                new Container(
                  width: 60.0,
                  height: 60.0,
                  margin: new EdgeInsets.all(8.0),
                  decoration: BoxDecoration(
                    image: DecorationImage(
                      image: new AssetImage('assets/imgs/ic_menu_pe.png'),
                      //从Assets加载图片
                      fit: BoxFit.cover,
                    ),
                    shape: BoxShape.circle,
                  ),
                ),
                new Text(
                  '查体育',
                  textAlign: TextAlign.center,
                )
              ],
            ),
            flex: 1,
          ),
          new Expanded(
            child: new Column(
              children: <Widget>[
                //头像
                new Container(
                  width: 60.0,
                  height: 60.0,
                  margin: new EdgeInsets.all(8.0),
                  decoration: BoxDecoration(
                    image: DecorationImage(
                      image: new AssetImage('assets/imgs/ic_menu_bus.png'),
                      //从Assets加载图片
                      fit: BoxFit.cover,
                    ),
                    shape: BoxShape.circle,
                  ),
                ),
                new Text(
                  '查校车',
                  textAlign: TextAlign.center,
                )
              ],
            ),
            flex: 1,
          ),
          new Expanded(
            child: new Column(
              children: <Widget>[
                //头像
                new Container(
                  width: 60.0,
                  height: 60.0,
                  margin: new EdgeInsets.all(8.0),
                  decoration: BoxDecoration(
                    image: DecorationImage(
                      image: new AssetImage('assets/imgs/ic_menu_system.png'),
                      //从Assets加载图片
                      fit: BoxFit.cover,
                    ),
                    shape: BoxShape.circle,
                  ),
                ),
                new Text(
                  '校园系统',
                  textAlign: TextAlign.center,
                )
              ],
            ),
            flex: 1,
          ),
          new Expanded(
            child: new Column(
              children: <Widget>[
                //头像
                new Container(
                  width: 60.0,
                  height: 60.0,
                  margin: new EdgeInsets.all(8.0),
                  decoration: BoxDecoration(
                    image: DecorationImage(
                      image: new AssetImage('assets/imgs/ic_menu_more.png'),
                      //从Assets加载图片
                      fit: BoxFit.cover,
                    ),
                    shape: BoxShape.circle,
                  ),
                ),
                new Text(
                  '更多',
                  textAlign: TextAlign.center,
                )
              ],
            ),
            flex: 1,
          ),
        ],
      ),
    );
  }
}

//今日课表
class TodayKb extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Padding(
      padding: new EdgeInsets.all(18.0),
      child: new Column(
        children: <Widget>[
          new Container(
            child: new Row(
              children: <Widget>[
                new Icon(
                  Icons.camera,
                  color: Colors.black26,
                  size: 17.0,
                ),
                new Container(
                  margin: new EdgeInsets.only(left: 5.0),
                  child: new Text(
                    '今日课表',
                    style: new TextStyle(color: Color(0xFF888888)),
                  ),
                )
              ],
            ),
          ),
          new Divider(
            color: Color(0xFF888888),
          ),
          new Container(
            margin: new EdgeInsets.only(top: 30.0, bottom: 2.0),
            child: new Text("今天竟然没有课~" + "\uD83D\uDE01"),
          ),
          new Container(
            margin: new EdgeInsets.only(top: 30.0, bottom: 2.0),
            child: new Text('点我查看完整课表',
                style: new TextStyle(
                    color: Color(
                      0xFF888888,
                    ),
                    fontSize: 12.0)),
          ),
        ],
      ),
    );
  }
}

//消息
class Message extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Padding(
      padding: new EdgeInsets.all(18.0),
      child: new Column(
        children: <Widget>[
          new Container(
            child: new Row(
              children: <Widget>[
                new Icon(
                  Icons.message,
                  color: Colors.black26,
                  size: 17.0,
                ),
                new Container(
                  margin: new EdgeInsets.only(left: 5.0),
                  child: new Text(
                    '消息',
                    style: new TextStyle(color: Color(0xFF888888)),
                  ),
                )
              ],
            ),
          ),
          new Divider(
            color: Color(0xFF888888),
          ),
          new Container(
            margin: new EdgeInsets.all(10.0),
            child: new Text("这里是消息"),
          ),
          new Divider(
            color: Color(0xFF888888),
          )
        ],
      ),
    );
  }
}

//日知录
class One extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new Padding(
      padding: new EdgeInsets.all(18.0),
      child: new Column(
        children: <Widget>[
          new Container(
            child: new Row(
              children: <Widget>[
                new Icon(
                  Icons.email,
                  color: Colors.black26,
                  size: 17.0,
                ),
                new Container(
                  margin: new EdgeInsets.only(left: 5.0),
                  child: new Text(
                    '日知录',
                    style: new TextStyle(color: Color(0xFF888888)),
                  ),
                )
              ],
            ),
          ),
          new Divider(
            color: Color(0xFF888888),
          ),
          new Container(
            margin: new EdgeInsets.all(10.0),
            child: new Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: <Widget>[
                new Text(
                  '2018/09/14',
                  style: new TextStyle(color: Color(0xFF888888)),
                ),
                new Margin(indent: 6.0),
                new Image(
                    image: new NetworkImage(
                        'http://image.wufazhuce.com/Fn5E1UnrcvN0jwFRiOtDZ2WnQa4N')),
                new Margin(indent: 6.0),
                new Text(
                  'Fahmi Ramadhan | 摄影',
                  style: new TextStyle(color: Color(0xFF888888)),
                ),
                new Margin(indent: 6.0),
                new Text(
                  '全部的爱情,都是两个心灵相通的人胜利,没法相互了解的人失败,没有所谓对错。',
                  textAlign: TextAlign.center,
                  style: new TextStyle(color: Color(0xFF888888)),
                ),
                new Margin(indent: 6.0),
                new Text(
                  '《东京爱情故事》',
                  style: new TextStyle(color: Color(0xFF888888)),
                )
              ],
            ),
          ),
          new Divider(
            color: Color(0xFF888888),
          )
        ],
      ),
    );
  }
}
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customview.dart

import 'package:flutter/material.dart';

//分隔栏
class BigDivider extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new SizedBox(
      height: 5.0,
      child: new Center(
        child: new Container(
          height: 5.0,
          color: Colors.black12,
        ),
      ),
    );
  }
}

//间隙
class Margin extends StatelessWidget {
  final double indent;

  const Margin({Key key, this.indent: 0.0}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return new Container(
      margin: new EdgeInsets.all(indent),
    );
  }
}
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