flutter框架一文通(一)

作者: 熊爸天下_56c7 | 来源:发表于2020-03-04 20:38 被阅读0次

第一部分 vscode终端操作快捷键第二部分 hello world程序第三部分常用组件

附:

flutter中文文档https://flutterchina.club/docs/
书籍:flutter实战 https://book.flutterchina.club/
flutter自动代码生成器 https://ui.flutterdart.cn/

第一部分 vscode终端操作快捷键：

运行模拟器：flutter run

更新页面：R

显示网格：P

android/IOS模式切换：O

关闭终端：Q

热更新方法：用debug，按照VS的提示配置即可，配置完成后如下

image

第二部分. 框架简介及hello world

一、总体架构

1、总体架构

image

其中engine部分：

skia 图形UI框架
dart 虚拟机dartVM
text 渲染纹理

其中Framework部分：

foundation：功能接口
animation：动画
painting：图像
gestures：触控
rendering：渲染
widgets：组件
meterial：googleUI风格
cupertino：IOSUI风格

2、GPU渲染

image

3.状态控制

image

4.Flutter理论基础知识

二、写一个hello world程序

主程序在main.dart里

image

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO
void main() => runApp(MyApp());         //main函数只有一句话:运行APP

class MyApp extends StatelessWidget{    //app继承于StatelessWidget组件对象
  @override                             //重构build方法
  Widget build(BuildContext context){  //组件的build的方法返回一个组件 参数是其上下文文件
    return MaterialApp(                 //返回方法 返回组件
      title: "welcome",                 //APP的title
      home: Scaffold(                   //APP的主体,其类型是一个脚手架Scaffold
        appBar: AppBar(                 //脚手架第一个组成是appbar
          title: Text("welcome to big bear's flutter!!!"),  //appbar的title
        ),
        body: Center(            //脚手架的第二个组成是body 给body一个center组件做内容
          child: Text("hello 熊爸haha!"),   //center里有一个子组件是 Text("???")
        ),
      ),
    );
  }
}

image

第三部分常用静态组件

statelesswidget 无状态变化的组件

statefullwidget 有状态变化的组件

一、文字组件 Text("")

image

1.textAlign （文本对齐）

Text的子属性，可传入TextAlign类对象，比如：

TextAlign.center 居中

TextAlign.left 左对齐

TextAlign.right 右对齐

TextAlign.start 和文字开始对齐

TextAlign.end 和文字结束对齐

image

2. maxLines （最大显示行数）

Text的子属性，可传入数值

Text(
            "hello 熊爸haha!锄禾日当午，汗滴禾下土。谁知盘中餐，粒粒皆辛苦。",
            textAlign: TextAlign.end,
            maxLines: 1,
            )

3. overflow 溢出处理

Text的子属性，可传入TextOverflow类对象

\begin{array}[a] {|a|ca|} \hline 对象 & 对象名称\ \hline TextOverflow.clip & 溢出裁剪 \ \hline TextOverflow.ellipsis & 溢出显示... \ \hline TextOverflow.fade &最后一行上下渐变 \ \hline \end{array}\

image

4. style 文字样式

Text的子属性，可传入TextStyle类对象

TextStyle类对象：

image

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO
void main() => runApp(MyApp());         //main函数只有一句话:运行APP

class MyApp extends StatelessWidget{    //app继承于StatelessWidget组件对象
  @override                             //重构build方法
  Widget build(BuildContext context){   //组件的build的方法返回一个组件 参数是其上下文文件
    return MaterialApp(                 //返回方法 返回组件
      title: "welcome",                 //APP的title
      home: Scaffold(                   //APP的主体,其类型是一个脚手架Scaffold
        appBar: AppBar(                 //脚手架第一个组成是appbar
          title: Text("welcome to big bear's flutter!!!"),  //appbar的title
        ),
        body: Center(                   //脚手架的第二个组成是body 给body一个center组件做内容
          child: Text(
            "hello 熊爸熊爸熊爸haha!锄禾日当午，汗滴禾下土。谁知盘中餐，粒粒皆辛苦。",
            textAlign: TextAlign.left,
            maxLines: 1,
            overflow: TextOverflow.ellipsis,
            style: TextStyle(
              fontSize: 25.0,
              color:Color.fromARGB(255, 220, 125, 125),
              decoration: TextDecoration.underline,
              decorationStyle: TextDecorationStyle.wavy,
            ),
            ), //center里有一个子组件是 Text("???")
        ),
      ),
    );
  }
}

image

二、container组件 container() 容器

container() 相当于HTML里的div

image

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO
void main() => runApp(MyApp());         //main函数只有一句话:运行APP

class MyApp extends StatelessWidget{    //app继承于StatelessWidget组件对象
  @override                             //重构build方法
  Widget build(BuildContext context){  //组件的build的方法返回一个组件 参数是其上下文文件
    return MaterialApp(                 //返回方法 返回组件
      title: "welcome",                 //APP的title
      home: Scaffold(                   //APP的主体,其类型是一个脚手架Scaffold
        appBar: AppBar(                 //脚手架第一个组成是appbar
          title: Text("welcome to big bear's flutter!!!"),  //appbar的title
        ),
        body: Center(            //脚手架的第二个组成是body 给body一个center组件做内容
          child: Container(
            height: 400.0,
            width: 300.0,
            //color: Colors.pinkAccent,
            margin: EdgeInsets.symmetric(horizontal: 010.0),
            decoration: new BoxDecoration(
              gradient: const LinearGradient(colors: [Colors.lightBlue,Colors.green],
                                            begin: Alignment.topLeft,
                                            end: Alignment.bottomRight,
                                            tileMode: TileMode.clamp,
                                            ),
              border: Border.all(width: 2.0,color: Colors.blueGrey),
              ),
            transform: Matrix4.rotationZ(0.1),
            alignment: Alignment.topLeft,
            padding: const EdgeInsets.fromLTRB(15.0, 30.0, 15.0, 0),
            child: Text(
              "锄禾日当午，汗滴禾下土，谁知盘中餐，粒粒皆辛苦！",
              style: TextStyle(
                fontSize: 24.0,
              ),
              maxLines: 1,
              overflow: TextOverflow.ellipsis,
              textAlign: TextAlign.center,
            ),
          ),   //center里有一个子组件是 Text("???")
        ),
      ),
    );
  }
}

image

三. image组件

image

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO
void main() => runApp(MyApp());         //main函数只有一句话:运行APP

class MyApp extends StatelessWidget{    //app继承于StatelessWidget组件对象
  @override                             //重构build方法
  Widget build(BuildContext context){  //组件的build的方法返回一个组件 参数是其上下文文件
    return MaterialApp(                 //返回方法 返回组件
      title: "welcome",                 //APP的title
      home: Scaffold(                   //APP的主体,其类型是一个脚手架Scaffold
        appBar: AppBar(                 //脚手架第一个组成是appbar
          title: Text("welcome to big bear's flutter!!!"),  //appbar的title
        ),
        body: Center(            //脚手架的第二个组成是body 给body一个center组件做内容
          child: Container(
            height: 600.0,
            width: 400.0,
            color: Colors.lightBlue,
            child: Image.network(
              "http://cms-bucket.ws.126.net/2019/1228/d84b26e0p00q37jrh002uc0009c005uc.png?imageView&thumbnail=200y140",
              fit: BoxFit.scaleDown,
              repeat: ImageRepeat.repeat,
              color: Colors.pinkAccent,
              colorBlendMode: BlendMode.darken,
            )
          ), 
        ),
      ),
    );
  }
}

四. Align组件 //对齐组件

image

五. Scaffold组件 //(脚手架)

脚手架是flutter页面框架结构中最重要的一环,他是页面的框架骨骼基础

image

六. AppBar组件 //APP导航条

image

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "TEST",
      home: Scaffold(
        appBar: AppBar(
        leading: Icon(Icons.home),
        title: Text("AppBar示例"),
        centerTitle: true,
        backgroundColor: Colors.deepPurpleAccent,
        actions: <Widget>[
          IconButton(icon: Icon(Icons.print), tooltip: 'print', onPressed: () {}),
          IconButton(icon: Icon(Icons.plus_one), tooltip: 'more', onPressed: () {}),
          IconButton(icon: Icon(Icons.share), tooltip: 'share', onPressed: () {}),
          PopupMenuButton(itemBuilder: 
            (context)=><PopupMenuItem<String>>[
              PopupMenuItem<String>(
                value: "share",
                child: Text("分享到朋友圈"),
              ),
              PopupMenuItem<String>(
                value: "quit",
                child: Text("退出"),
              )
            ]
          )
        ],
      ),
        body: Container(),
      ),
    );
  }
}

image

七. FloatingActionButton //悬浮按钮组件

image

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "TEST",
      home: Scaffold(
        appBar: AppBar(
          title: Text("data"),
        ),
        floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
        floatingActionButton: FloatingActionButton(
          tooltip: "小贴士,解释按键后会发生什么",
          foregroundColor: Colors.black87,
          backgroundColor: Colors.amberAccent,
          hoverColor: Colors.deepPurple,
          focusColor: Colors.deepPurpleAccent,
          splashColor: Colors.greenAccent,
          highlightElevation: 5,
          hoverElevation: 15,
          elevation: 5,
          focusElevation: 10,
          autofocus: true,
          mini: true,
          child: Icon(Icons.add),
          onPressed: () {},
        ),
        body: Container(),
      ),
    );
  }
}

image

八. BottomAppBar组件 //底部导航条

image

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "TEST",
      home: Scaffold(
        appBar: AppBar(title: Text("data"),),
        floatingActionButtonLocation: FloatingActionButtonLocation.centerDocked,
        floatingActionButton: FloatingActionButton(
          child: Icon(Icons.add),
          onPressed: (){},
        ),

        bottomNavigationBar: BottomAppBar(
          notchMargin: 10.0,
          color: Colors.amber, 
          elevation: 10,
          child: Row(
            mainAxisSize: MainAxisSize.max,
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
           children: <Widget>[
             IconButton(icon: Icon(Icons.search), onPressed: (){}),
             IconButton(icon: Icon(Icons.menu), onPressed: (){}),
           ], 
          ),
        ),
        body: Container(),
      ),
    );
  }
}

image

九. ButtonBar //按钮条组件

image

十. NestedScrollView //可嵌套的滚动视图结构

image

十一. SliverAppBar //可扩展折叠的滚动工具栏

SliverAppBar 必须作为NestedScrollView 的子项才有用!!!!

image

十一. FlexibleSpaceBar组件 //可折叠空间组件

FlexibleSpaceBar必须作为SliverAppBar的子项才有用!!!!

image

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "TEST",
      home: Scaffold(
        appBar: AppBar(
          title: Text("data"),
        ),
        body: NestedScrollView(
            headerSliverBuilder: (context, beScrolled) {
              return <Widget>[
                (
                  centerTitle: true,
                  expandedHeight: 200,
                  floating: false,
                  pinned: true,
                  flexibleSpace: FlexibleSpaceBar(
                    background: Image.network(
                      "https://ss1.bdstatic.com/70cFuXSh_Q1YnxGkpoWK1HF6hhy/it/u=793051438,2878586275&fm=11&gp=0.jpg",
                      fit: BoxFit.cover,
                    ),
                    title: Text("可折叠组件"),
                  ),
                )
              ];
            },
            body: Center()),
      ),
    );
  }
}

image

十二. listView组件列表布局

ListView的children是组件类型，所以可以随便添加任意组件

image

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO
void main() => runApp(MyApp());         //main函数只有一句话:运行APP

class MyApp extends StatelessWidget{    //app继承于StatelessWidget组件对象
  @override                             //重构build方法
  Widget build(BuildContext context){  //组件的build的方法返回一个组件 参数是其上下文文件
    return MaterialApp(                 //返回方法 返回组件
      title: "welcome",                 //APP的title
      home: Scaffold(                   //APP的主体,其类型是一个脚手架Scaffold
        appBar: AppBar(                 //脚手架第一个组成是appbar
          title: Text("welcome to big bear's flutter!!!"),  //appbar的title
        ),
        body: Center(
          child: Container(
            height: 200,
            color: Colors.pinkAccent,
            child: MyList001(),
          ),
        )
      ),
    );
  }
}
class MyList001 extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    return ListView(
              scrollDirection: Axis.horizontal,
              children: <Widget>[
              Container(width: 180,color: Colors.lightBlue,),  
              Container(width: 180,color: Colors.pinkAccent,),
              Container(width: 180,color: Colors.lightGreen,),
              Container(width: 180,color: Colors.deepPurple,),                    
              ],
            );
  }
}

动态列表（参数传递内容的列表）

import 'package:flutter/material.dart'; 
void main() => runApp(MyApp(
  items:List<String>.generate(15,(i)=>"Item $i")  //在myapp类里创建了一个属性叫items，它里面有一个列表
                      //里面的(i)=>"Item $i"是自动生成列表的项，就像python 列表中可以写lambda表达式一样
));

class MyApp extends StatelessWidget{    
  final List<String> items;            //类中建立属性items 
  MyApp({Key key,@required this.items}):super(key:key); 
  //Key key                  重写构造函数默认传入的
  //@required this.items     限定修饰  this.items必须传入
  //:super(key:key) 调用祖先/父类无名无参构造函数，StatelessWidget 所以需要super往上找
  @override                             
  Widget build(BuildContext context){  
    return MaterialApp(                 
      title: "welcome",                 
      home: Scaffold(                   
        body:ListView.builder(               //用专门的builder方法构建动态列表
          itemCount: items.length,           //传入项目的数量
          itemBuilder: (context,index){      //传入context上下文，同时传入index 
                                             //这里有点像JS，把下文中需要的参数实现一下
            return ListTile(                 //listTile listview的项目瓦片
              title: Text("${items[index]}"), //通过重构函数，我们将外部的信息传入了动态列表中
            );
          },
        )
      ),
    );
  }
}

十三. 网格列表布局

image

import 'package:flutter/material.dart'; 
void main() => runApp(MyApp());

class MyApp extends StatelessWidget{    
  @override                             
  Widget build(BuildContext context){  
    return MaterialApp(                 
      title: "welcome",                 
      home: Scaffold(
        appBar: AppBar(
          title: Text("dasdasdas"),
        ),                   
        body:MyGridList(),
      ),
    );
  }
}
class MyGridList extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    return GridView.count(
          padding: EdgeInsets.all(5.0),
          crossAxisSpacing:5,
          crossAxisCount: 3,
          mainAxisSpacing: 5,
          childAspectRatio: 0.7,
          children: <Widget>[
            Image.network("https://image11.m1905.cn/uploadfile/2019/0829/thumb_1_150_203_20190829041446876955.jpg",fit: BoxFit.cover,),
            Image.network("https://image11.m1905.cn/uploadfile/2019/1227/thumb_1_150_203_20191227090512473043.jpg",fit: BoxFit.cover,),
            Image.network("https://image11.m1905.cn/uploadfile/2019/0123/thumb_1_150_203_20190123044311875088.jpg",fit: BoxFit.cover,),
            Image.network("https://image11.m1905.cn/uploadfile/2018/0209/thumb_1_150_203_20180209015612332245.jpg",fit: BoxFit.cover,),
            Image.network("https://image11.m1905.cn/uploadfile/2014/0812/thumb_1_150_203_20140812031906771224.jpg",fit: BoxFit.cover,),
            Image.network("https://image11.m1905.cn/uploadfile/2009/1106/thumb_1_150_203_20091106112530726.jpg",fit: BoxFit.cover,),
            Image.network("https://img3.doubanio.com/view/photo/s_ratio_poster/public/p2577327061.webp",fit: BoxFit.cover,),
            Image.network("https://img9.doubanio.com/view/photo/s_ratio_poster/public/p2578045524.jpg",fit: BoxFit.cover,),
            Image.network("https://img3.doubanio.com/view/photo/s_ratio_poster/public/p2556824333.jpg",fit: BoxFit.cover,),
            Image.network("https://img1.doubanio.com/view/photo/s_ratio_poster/public/p2574764569.jpg",fit: BoxFit.cover,),
            Image.network("https://img3.doubanio.com/view/photo/s_ratio_poster/public/p2568258113.jpg",fit: BoxFit.cover,),
            Image.network("https://img1.doubanio.com/view/photo/s_ratio_poster/public/p2541280047.jpg",fit: BoxFit.cover,),
          ],
          );
  }
}

按拓展性构建动态网格

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO

void main() => runApp(MaterialApp(
      title: "组件",
      home: MyApp(),
    )); //main函数只有一句话:运行APP

class MyApp extends StatelessWidget {
  List<Container> _buildList(int count) {
    return List<Container>.generate(
      count,
      (int index) => Container(child: Image.asset('images/${index + 1}.jpg')),
    );
  }

  //app继承于StatelessWidget组件对象
  @override //重构build方法
  Widget build(BuildContext context) {
    //组件的build的方法返回一个组件 参数是其上下文文件
    return Scaffold(
      appBar: AppBar(
        title: Text("data"),
      ),
      body: GridView.extent(
        maxCrossAxisExtent: 150.0,
        padding: EdgeInsets.all(4.0),
        mainAxisSpacing: 4.0,
        crossAxisSpacing: 4.0,
        children: _buildList(9),
      ),
    );
  }
}

image

十四. 按钮组件

image

十五. 水平布局

Row组件水平布局，搭配Expanded组件可实现灵活的水平布局

对Row来说主轴是水平方向

image

import 'package:flutter/material.dart'; 
void main() => runApp(MyApp());

class MyApp extends StatelessWidget{    
  @override                             
  Widget build(BuildContext context){  
    return MaterialApp(                 
      title: "welcome",                 
      home: Scaffold(
        appBar: AppBar(
          title: Text("熊爸"),
        ),                   
        body:Row(

          children: <Widget>[
            RaisedButton(
              onPressed: (){print("点击了");},
              color: Colors.amberAccent,
              child: Text("amberAccent"),
            ),
            Expanded(child: RaisedButton(
              onPressed: (){print("点击了");},
              color: Colors.lightBlue,
              child: Text("lightBlue"),
            ),),
            Expanded(child: RaisedButton(
              onPressed: (){print("点击了");},
              color: Colors.pinkAccent,
              child: Text("pinkAccent"),
            ),)
          ],
        ),
      ),
    );
  }
}

十六. 垂直布局

image

对Row来说主轴是垂直方向

import 'package:flutter/material.dart'; 
void main() => runApp(MyApp());

class MyApp extends StatelessWidget{    
  @override                             
  Widget build(BuildContext context){  
    return MaterialApp(                 
      title: "welcome",                 
      home: Scaffold(
        appBar: AppBar(
          title: Text("熊爸"),
        ),                   
        body:Column(
          crossAxisAlignment: CrossAxisAlignment.center,
          children: <Widget>[
            Text("熊爸"),
            Expanded(child: Text("锄禾日当午，汗滴禾下土。谁知盘中餐，粒粒皆辛苦。"),),
            Text("data"),
          ],
        ),
      ),
    );
  }
}

十七. Stack组件、Position组件（层叠布局）

两层堆叠用Stack组件

多层堆叠用Position组件

image

import 'package:flutter/material.dart'; 
void main() => runApp(MyApp());

class MyApp extends StatelessWidget{    
  @override                             
  Widget build(BuildContext context){  
    return MaterialApp(                 
      title: "welcome",                 
      home: Scaffold(
        appBar: AppBar(
          title: Text("熊爸"),
        ),                   
        body:Stack(
          alignment: FractionalOffset(0.5,0.9),
          children: <Widget>[
            CircleAvatar(child: Text("一部电影"),radius: 200,foregroundColor: Colors.purple,backgroundImage: NetworkImage("https://img9.doubanio.com/view/photo/s_ratio_poster/public/p2578045524.jpg"),),
            Container(
              width: 100,
              height: 50,
              color: Colors.lightBlue,
              alignment: Alignment.center,
              child: Text("本月最佳",style: TextStyle(color: Colors.white),),
            )
          ],
        ),
      ),
    );
  }
}

image

import 'package:flutter/material.dart'; 
void main() => runApp(MyApp());

class MyApp extends StatelessWidget{    
  @override                             
  Widget build(BuildContext context){  
    return MaterialApp(                 
      title: "welcome",                 
      home: Scaffold(
        appBar: AppBar(
          title: Text("熊爸"),
        ),                   
        body:Stack(
          alignment: FractionalOffset(0.5,0.9),
          children: <Widget>[
            CircleAvatar(child: Text("一部电影"),radius: 200,foregroundColor: Colors.purple,backgroundImage: NetworkImage("https://img9.doubanio.com/view/photo/s_ratio_poster/public/p2578045524.jpg"),),
            Positioned(
              top: 10.0,
              left: 20.0,
              child: Text("haha")
            ),
            Positioned(
              bottom: 10.0,
              right: 20.0,
              child: Text("OKOK")
            ),
          ],
        ),
      ),
    );
  }
}

十八. 圆盘组件

image

十九. 瓦片组件

image

二十. 卡片布局

image

import 'package:flutter/material.dart'; 
void main() => runApp(MyApp());

class MyApp extends StatelessWidget{    
  @override                             
  Widget build(BuildContext context){  
    return MaterialApp(                 
      title: "welcome",                 
      home: Scaffold(
        appBar: AppBar(
          title: Text("熊爸"),
        ),                   
        body:Card(
          borderOnForeground: true,
          child: Column(
            children: <Widget>[
              ListTile(
                title: Text("anny baby",style: TextStyle(fontSize: 24,fontWeight: FontWeight.bold),),
                subtitle: Text("a lovely girl"),
                leading: CircleAvatar(backgroundImage: NetworkImage("https://img3.doubanio.com/view/photo/s_ratio_poster/public/p2572847101.webp"),),
              ),
              Divider(),
              ListTile(
                title: Text("anny baby",style: TextStyle(fontSize: 24,fontWeight: FontWeight.bold),),
                subtitle: Text("a lovely girl"),
                leading: Icon(Icons.satellite),
                trailing: Icon(Icons.keyboard_arrow_right),
              ),
              Divider(),
              ListTile(
                title: Text("anny baby",style: TextStyle(fontSize: 24,fontWeight: FontWeight.bold),),
                subtitle: Text("a lovely girl"),
                leading: Icon(Icons.satellite),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

例2:

import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "TEST",
      home: Scaffold(
        appBar: AppBar(title: Text("FlatButton")),
        body: Column(
          children: <Widget>[
            Card(
              color: Colors.red[100],
              margin: EdgeInsets.all(10),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: <Widget>[
                  ListTile(
                    leading: Icon(Icons.shopping_basket),
                    title: Text(
                      "一加手机 OnePlus7pro",
                      style: TextStyle(fontSize: 25),
                    ),
                    subtitle: Text("8+256G"),
                    contentPadding: EdgeInsets.all(10),
                    trailing: Text(
                      "￥3999",
                      style:
                          TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
                    ),
                  ),
                  ButtonBar(
                    children: <Widget>[
                      FlatButton.icon(
                          textColor: Colors.deepPurple,
                          onPressed: () {},
                          icon: Icon(Icons.shopping_cart),
                          label: Text("购买")),
                      FlatButton.icon(
                          textColor: Colors.redAccent,
                          onPressed: () {},
                          icon: Icon(Icons.favorite),
                          label: Text("收藏")),
                    ],
                  )
                ],
              ),
            ),
            Card(
              color: Colors.orange,
              margin: EdgeInsets.all(10),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: <Widget>[
                  ListTile(
                    leading: Icon(Icons.shopping_basket),
                    title: Text(
                      "小米手机 CC9",
                      style: TextStyle(fontSize: 25),
                    ),
                    subtitle: Text("8+256G"),
                    contentPadding: EdgeInsets.all(10),
                    trailing: Text(
                      "￥1999",
                      style:
                          TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
                    ),
                  ),
                  ButtonBar(
                    children: <Widget>[
                      FlatButton.icon(
                          textColor: Colors.deepPurple,
                          onPressed: () {},
                          icon: Icon(Icons.shopping_cart),
                          label: Text("购买")),
                      FlatButton.icon(
                          textColor: Colors.redAccent,
                          onPressed: () {},
                          icon: Icon(Icons.favorite),
                          label: Text("收藏")),
                    ],
                  )
                ],
              ),
            ),
            Card(
              color: Colors.green,
              margin: EdgeInsets.all(10),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: <Widget>[
                  ListTile(
                    leading: Icon(Icons.shopping_basket),
                    title: Text(
                      "OPPO手机 FindX2",
                      style: TextStyle(fontSize: 25),
                    ),
                    subtitle: Text("8+256G"),
                    contentPadding: EdgeInsets.all(10),
                    trailing: Text(
                      "￥3599",
                      style:
                          TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
                    ),
                  ),
                  ButtonBar(
                    children: <Widget>[
                      FlatButton.icon(
                          textColor: Colors.deepPurple,
                          onPressed: () {},
                          icon: Icon(Icons.shopping_cart),
                          label: Text("购买")),
                      FlatButton.icon(
                          textColor: Colors.redAccent,
                          onPressed: () {},
                          icon: Icon(Icons.favorite),
                          label: Text("收藏")),
                    ],
                  )
                ],
              ),
            ),
            Card(
              color: Colors.blueGrey,
              margin: EdgeInsets.all(10),
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: <Widget>[
                  ListTile(
                    leading: Icon(Icons.shopping_basket),
                    title: Text(
                      "华为手机 Mate30",
                      style: TextStyle(fontSize: 25),
                    ),
                    subtitle: Text("8+256G"),
                    contentPadding: EdgeInsets.all(10),
                    trailing: Text(
                      "￥3799",
                      style:
                          TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
                    ),
                  ),
                  ButtonBar(
                    children: <Widget>[
                      FlatButton.icon(
                          textColor: Colors.deepPurple,
                          onPressed: () {},
                          icon: Icon(Icons.shopping_cart),
                          label: Text("购买")),
                      FlatButton.icon(
                          textColor: Colors.redAccent,
                          onPressed: () {},
                          icon: Icon(Icons.favorite),
                          label: Text("收藏")),
                    ],
                  )
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}

image

二十一. 分割线组件

Divider()

二十二. 导航

Navigator.push(context, route); //压栈,压入下一页

Navigator.pop(context); //弹栈,弹出一层

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO

void main() => runApp(MaterialApp(
      title: "组件",
      home: MyApp(),
    )); //main函数只有一句话:运行APP

class FirstPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("第一页"),
      ),
      body: Center(
        child: RaisedButton(
          child: Text("进入第二页"),
          onPressed: () {
            Navigator.push(
                context, MaterialPageRoute(builder: (context) => SecondPage()));
          },
        ),
      ),
    );
  }
}

class SecondPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("第二页"),
      ),
      body: Column(
          children: <Widget>[
            RaisedButton(
              child: Text("返回"),
              onPressed: () {
                Navigator.pop(context);
              },
            ),
            RaisedButton(
              child: Text("进入第三页"),
              onPressed: (){
                Navigator.push(context, MaterialPageRoute(builder: (context)=>ThirdPage()));
              },
            ),
          ],
        ),
    );
  }
}

class ThirdPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("第三页"),
      ),
      body: Center(
        child: RaisedButton(
          child: Text("返回"),
          onPressed: () {
            Navigator.pop(context);
          },
        ),
      ),
    );
  }
}

class MyApp extends StatelessWidget {
  //app继承于StatelessWidget组件对象
  @override //重构build方法
  Widget build(BuildContext context) {
    //组件的build的方法返回一个组件 参数是其上下文文件
    return FirstPage();
  }
}

image

二十三. 带参数传递的导航

Navigator.push(context, MaterialPageRoute(builder: ( (context)=>SecPage(product: products[index],) )));

其实就是在构造函数中传递.

import 'package:flutter/material.dart';

class Product {
  final String title;
  final String description;
  Product(this.title,this.description);
}
void main() {
  runApp(MyApp(products: List.generate(50,(i)=>Product("商品$i","这是一个商品详情，编号为$i")),));
}

class MyApp extends StatelessWidget {
  final List<Product> products;
  const MyApp({Key key,@required this.products}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
    title: "test1",
    home: ProductList(
      products:List.generate(products.length, (i)=>products[i])),
    );
  }
}
class ProductList extends StatelessWidget {
  final List<Product> products;
  const ProductList({Key key,@required this.products}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("products"),),
      body: ListView.builder(
        itemCount: products.length,
        itemBuilder: (BuildContext context, int index) {
        return ListTile(
          title: Text(products[index].title),
          onTap: (){
            Navigator.push(context, MaterialPageRoute(
              builder: (context)=>SecondPage(product: products[index],)
            ));
          },
        );
       },
      ),
      );
  }
}
class SecondPage extends StatelessWidget {
  final Product product;
  const SecondPage({Key key,@required this.product}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("商品详情"),),
      body: Text(product.description),
    );
  }
}

例二:页面跳转发送数据

import 'package:flutter/material.dart';

class Product {
  final String title;
  final String description;
  Product(this.title, this.description);
}

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "页面间数据传递",
      home: ProductList(
        products: List.generate(20, (i) => "$i"),
      ),
    );
  }
}

class ProductList extends StatelessWidget {
  final List<String> products;
  ProductList({Key key, @required this.products}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(title: Text("商品汇总页")),
        body: ListView.builder(
          itemCount: products.length,
          itemBuilder: (context, index) {
            return ListTile(
              title: Text("这是商品:$index"),
              onTap: () {
                Navigator.push(
                    context,
                    MaterialPageRoute(
                        builder: ((context) => SecPage(
                              product: Product("$index","这件$index 号商品是我们村的爆款哦!"),
                            ))));
              },
            );
          },
        ));
  }
}

class SecPage extends StatelessWidget {
  final Product product;
  SecPage({Key key, @required this.product}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("$product 的商品详情")),
      body: Center(
        child: Column(
          children: <Widget>[
            Text(
              "商品显示在这里,商品编号:${product.title},\n商品描述:${product.description}.\n它$product 非常诱人!!\n您还在犹豫个啥???😡",
              style: TextStyle(fontSize: 20),
            ),
            RaisedButton(
              child: Text("返回"),
              onPressed: () {
                Navigator.pop(context);
              },
            ),
          ],
        ),
      ),
    );
  }
}

image

例三:页面跳转返回数据

二十四. 异步请求和等待

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO
void main(){
  runApp(MaterialApp(
    title: "页面跳转",
    home:FirstPage(),
  ));
}
class FirstPage extends StatelessWidget {
  const FirstPage({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("dataa"),),
      body: Center(child:RouteBut()),
    );
  }
}
class RouteBut extends StatelessWidget {
  const RouteBut({Key key}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return RaisedButton(
      shape: StadiumBorder(),
      onPressed: (){
        _navi_in(context);
      },
      color: Colors.lightBlue,
      child: Text("进入"),
    );
  }
  _navi_in(BuildContext context) async{
    final result=await Navigator.push(context,
    MaterialPageRoute(
      builder: (contex)=>SecondPage()
    )
    );
    Scaffold.of(context).showSnackBar(SnackBar(content: Text(result),));
  }
}
class SecondPage extends StatelessWidget {
  const SecondPage({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      child: Scaffold(
        appBar: AppBar(title: Text("设置返回数据"),),
        body: Center(
          child: Column(
            children: <Widget>[
              RaisedButton(
                child: Text("返回数据1"),
                onPressed: (){
                  Navigator.pop(context,"数据1");
                },
              ),
              RaisedButton(
                child: Text("返回数据2"),
                onPressed: (){
                  Navigator.pop(context,"数据2");
                },
              ),
            ],
          ),
        ),
      ),
    );
  }
}

二十五. 加载静态资源

在项目里创建一个资源文件夹,放入资源

image

找到pubspec.yaml文件并打开

image

注册资源:

image

注册后就可以引用了

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO
void main()=>runApp(MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return  MaterialApp(
      title: "myAPP",
      home: Scaffold(
        appBar: AppBar(title: Text("daaata"),),
        body:Container(
          child: Image.asset("images/test1.jpg"),
        )
      ),
    );
  }
}

二十六. Expanded //拓展组件

Expanded 组件可以让 Row、Column、Flex等子组件在其主轴方向上展开并填充可用空间。类似 Android 中的 widget 属性的用法

image

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO

void main() => runApp(MyApp()); //main函数只有一句话:运行APP

class MyApp extends StatelessWidget {
  //app继承于StatelessWidget组件对象
  @override //重构build方法
  Widget build(BuildContext context) {
    //组件的build的方法返回一个组件 参数是其上下文文件
    final mytitle = "listview";
    return MaterialApp(
      //返回方法 返回组件
      title: mytitle, //APP的title
      home: Scaffold(
          //APP的主体,其类型是一个脚手架Scaffold
          appBar: AppBar(
            //脚手架第一个组成是appbar
            title: Text(mytitle), //appbar的title
          ),
          body: Row(
            children: <Widget>[
              Image.network(
                "https://i0.hdslb.com/bfs/bangumi/b919ca54abfa2aaed952f197da67211118944923.jpg@144w_144h.webp",
                width: 50,
              ),
              Text("这是一个非常非常非常非常长的句子!!!长到这个ROW放不下了!!!"),
              Icon(Icons.sentiment_satisfied),
            ],
          )),
    );
  }
}

image

如果用上expanded组件则:

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO

void main() => runApp(MyApp()); //main函数只有一句话:运行APP

class MyApp extends StatelessWidget {
  //app继承于StatelessWidget组件对象
  @override //重构build方法
  Widget build(BuildContext context) {
    //组件的build的方法返回一个组件 参数是其上下文文件
    final mytitle = "listview";
    return MaterialApp(
      //返回方法 返回组件
      title: mytitle, //APP的title
      home: Scaffold(
          //APP的主体,其类型是一个脚手架Scaffold
          appBar: AppBar(
            //脚手架第一个组成是appbar
            title: Text(mytitle), //appbar的title
          ),
          body: Row(
            children: <Widget>[
              Image.network(
                "https://i0.hdslb.com/bfs/bangumi/b919ca54abfa2aaed952f197da67211118944923.jpg@144w_144h.webp",
                width: 50,
              ),
              Expanded(child: Text("这是一个非常非常非常非常长的句子!!!长到这个ROW放不下了!!!所以expanded组件就自动修改了一下文本样式,终于让ROW能显示了!!!"),),
              Icon(Icons.sentiment_satisfied),
            ],
          )),
    );
  }
}

image

二十七. sizebox盒模型

image

二十八. GestureDetector组件(手势监听)

image

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO

void main() => runApp(MaterialApp(
      title: "组件",
      home: MyApp(),
    )); //main函数只有一句话:运行APP

class Mybutton extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: (){
        final mysnak=SnackBar(content: Text("触发ontap,冒出提示框!!"));
        Scaffold.of(context).showSnackBar(mysnak);
      },
      child: Container(
       padding: EdgeInsets.all(12.0),
       decoration: BoxDecoration(
       color: Theme.of(context).buttonColor,
       borderRadius: BorderRadius.circular(10.0),  
       ), 
       child: Text("点一下"),
      ),
    );
  }
}
class MyApp extends StatelessWidget {
  //app继承于StatelessWidget组件对象
  @override //重构build方法
  Widget build(BuildContext context) {
    //组件的build的方法返回一个组件 参数是其上下文文件
    return Scaffold(
      appBar: AppBar(
        title: Text("data"),
      ),
      body: Center(child:Mybutton()),
    );
  }
}

image

二十九. Dismissible组件(滑动删除)

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO

void main() => runApp(MaterialApp(
      title: "组件",
      home: MyApp(),
    )); //main函数只有一句话:运行APP

class MyApp extends StatelessWidget {
  List<String> items = List<String>.generate(30, (i) => "item${i + 1}");
  //app继承于StatelessWidget组件对象
  @override //重构build方法
  Widget build(BuildContext context) {
    //组件的build的方法返回一个组件 参数是其上下文文件
    return Scaffold(
      appBar: AppBar(
        title: Text("data"),
      ),
      body: ListView.builder(
        itemCount: items.length,
        itemBuilder: (context, index) {
          return Dismissible(
            key: Key(items[index]),
            onDismissed: (derction) {
              items.removeAt(index);
              Scaffold.of(context)
                  .showSnackBar(SnackBar(content: Text("data:$derction")));
            },
            child: ListTile(
              title: Text("列表${items[index]}"),
            ),
          );
        },
      ),
    );
  }
}

image

三十. SnackBar

image

Scaffold.of(context).showSnackBar(SnackBar(content: Text("data:$derction")));

例2:

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        title: "TEST",
        home: Scaffold(
            appBar: AppBar(
              title: Text("data"),
            ),
            body: Center(
              child: MyBut1(),
            )));
  }
}

class MyBut1 extends StatelessWidget {
  final mySnak1 = SnackBar(
    content: Row(
      children: <Widget>[
        Icon(Icons.cake),
        Text("感谢点击!!"),
      ],
    ),
    backgroundColor: Colors.deepPurpleAccent,
    //持续时间
    duration: Duration(milliseconds: 1500),
    //反馈动作
    action: SnackBarAction(
        label: "OK", textColor: Colors.greenAccent, onPressed: () {}),
  );
  @override
  Widget build(BuildContext context) {
    return RaisedButton(
      child: Text("点击出现snackBar"),
      onPressed: () {
        Scaffold.of(context).showSnackBar(mySnak1);
      },
    );
  }
}

image

三十一. 自定义字体

1.新建字体文件夹font 并放入字体文件

image

2.在pubspec.yaml文件中注册字体.

image

3.在程序中引用

import 'package:flutter/material.dart'; // 一个UI库 www.Material.IO

void main() => runApp(MaterialApp(
      title: "组件",
      home: MyApp(),
    )); //main函数只有一句话:运行APP

class MyApp extends StatelessWidget {
  List<String> items = List<String>.generate(30, (i) => "item${i + 1}");
  //app继承于StatelessWidget组件对象
  @override //重构build方法
  Widget build(BuildContext context) {
    //组件的build的方法返回一个组件 参数是其上下文文件
    return Scaffold(
      appBar: AppBar(
        title: Text("data"),
      ),
      body: Center(
        child: Text(
          "自定d义字体1data!!?!!@#%@#abasdasdaxkl123454563😀",
          style: TextStyle(
            fontSize: 25,
            fontFamily: "xkzzt",
          ),
        ),
      ),
    );
  }
}

三十二. hero组件 //页面过度动画

image

注意:要过渡的两个页面应该设置同样的tag

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "test",
      home: FirstPage(),
    );
  }
}

class FirstPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("第一页"),
      ),
      body: GestureDetector(
          child: Hero(
            tag: "pic1",
            child: Icon(Icons.picture_in_picture),),
          onTap: () {
            Navigator.push(
                context, MaterialPageRoute(builder: (contex) => SecPage()));
          },
      ),
    );
  }
}

class SecPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text("第二页")),
      body: Center(
        child: GestureDetector(
          child: Hero(
            tag: "pic1",
            child: Image.network(
                "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1581017576843&di=e5876e0581a47faa82797803e4949794&imgtype=0&src=http%3A%2F%2F5b0988e595225.cdn.sohucs.com%2Fimages%2F20180910%2Ff96bbc903e094492a571515d0e417bf3.jpeg"),
          ),
          onTap: () {
            Navigator.pop(context);
          },
        ),
      ),
    );
  }
}

image

三十三. ConstrainedBox //可伸缩盒子

伸缩盒子给子组件限定了一个最大和最小空间,子组件不得超过此空间.

image

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        title: "TEST",
        home: Scaffold(
          appBar: AppBar(title: Text("ConstrainedBox")),
          body: Container(
            height: 500,
            child: ConstrainedBox(
              constraints: BoxConstraints(
                maxWidth:300,              
                minHeight: 200,
                maxHeight: 500,
                minWidth: 200,
                ),
              child: Container(
                width: 0,
                height: 600, 
                color: Colors.redAccent,
              ),  
              ),
          ),
        ));
  }
}

三十四. DecoratedBox //带装饰的盒子

image

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        title: "TEST",
        home: Scaffold(
          appBar: AppBar(title: Text("bottomNavigatorBar")),
          body: Center(
            child: Container(
              width: 350,
              height: 600,
              child: DecoratedBox(
                position: DecorationPosition.foreground,
                //决定装饰器位置,会不会遮挡child里的组件
                decoration: BoxDecoration(
                  color: Colors.teal,
                  image: DecorationImage(
                    image: NetworkImage(
                        'http://a1.att.hudong.com/05/00/01300000194285122188000535877.jpg'),
                  ),
                  borderRadius: BorderRadius.circular(20),
                  backgroundBlendMode: BlendMode.colorBurn,
                  border: Border.all(
                    width: 6,
                    color: Colors.black38,
                  ),
                  //shape: BoxShape.rectangle
                ),
                child: Text(
                  "可爱可爱小猫咪",
                  style: TextStyle(fontSize: 25),
                ),
              ),
            ),
          ),
        ));
  }
}

image

三十五. FittedBox //自适应填充盒模型

此盒子允许他的子组件有自适应性

image

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "TEST",
      home: Scaffold(
        appBar: AppBar(title: Text("FittedBox")),
        body: Column(
          children: <Widget>[
            Container(
              width: 200,
              height: 100,
              color: Colors.greenAccent,
              child: FittedBox(
                fit: BoxFit.fill,
                alignment: Alignment.center,
                child: Text("使用fill模式自适应"),
              ),
            )
          ],
        ),
      ),
    );
  }
}

image

三十六. OverflowBox //允许溢出的盒模型

此盒子允许他的子组件溢出

image

三十七. RotatedBox //允许旋转盒模型

此盒子允许他的子组件旋转,会顺时针旋转 quarterTurns × 90°

image

注意data的方向

三十八. SizedBox //限定大小的盒模型

image

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "TEST",
      home: Scaffold(
        appBar: AppBar(title: Text("RotatedBox")),
        body: SizedBox(
            width: 200,
            height: 200,
            child: Container(
              width: 400,
              height: 100,
              color: Colors.blue,
            )),
      ),
    );
  }
}

image

子组件设置了宽高,但不管用了

三十九. FlatButton //扁平按钮组件

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "TEST",
      home: Scaffold(
        appBar: AppBar(title: Text("FlatButton")),
        body: Center(
          child: Column(
            children: <Widget>[
              FlatButton(
                child: Text("data"),
                colorBrightness: Brightness.dark,
                onHighlightChanged: (n) {},
                onPressed: () {},
                onLongPress: () {},
                color: Colors.pinkAccent,
              ),
              FlatButton.icon(
                  color: Colors.amberAccent,
                  onPressed: () {},
                  icon: Icon(Icons.history),
                  label: Text("null")),
            ],
          ),
        ),
      ),
    );
  }
}

image

四十. IconButton //图标按钮组件

image

四十一 OutlineButton //外边线按钮组件

image

四十二. RawMaterialButton //原始按钮组件

image

第四部分常用动态组件

一. tabbar组件 //选项卡

选项卡是一个动态组件,动态组件创建如下:

image

创建步骤:

1.在appbar中加一个tabbar

2.在body中加一个tabbarview

3.制作一个控制器_tabController来关联上面的二者

4.重写initState() dispose() 用来实现上述控制器

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(title: "TEST", home: Demo());
  }
}

class Demo extends StatefulWidget {
  @override
  _DemoState createState() => _DemoState();//重写创建状态
}

class _DemoState extends State<Demo> with SingleTickerProviderStateMixin {//必须加SingleTickerProviderStateMixin
  ScrollController _scrollController;    //类内声明了一个ScrollController组件,名叫_scrollController
  TabController _tabController;//类内声明了一个TabController组件,名叫_tabController
  @override
  void initState() {        //重写初始化状态函数
    super.initState();      //必须先继承父类
    _scrollController = ScrollController();  //初始化时创建一个ScrollController,赋值给_scrollController
    _tabController = TabController(length: 6, vsync: this);//初始化时创建一个TabController,赋值给_tabController
    //length必须与选项卡数量对应  
  }

  @override
  void dispose() {   //重写释放函数
    _scrollController.dispose();  //注销_scrollController组件
    _tabController.dispose();//注销_tabController组件
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        leading: Icon(Icons.home),
        title: Text("tabBar"),
        bottom: TabBar(          //在APPBAR的底部加一个tabbar
          controller: _tabController,   //控制器为_tabController
          tabs: <Widget>[    //里面的Tab
            Tab(text: '语文',icon: Icon(Icons.font_download),),
            Tab(text: '数学',icon: Icon(Icons.format_list_numbered),),
            Tab(text: '英语',icon: Icon(Icons.nature),),
            Tab(text: '历史',icon: Icon(Icons.history),),
            Tab(text: '地理',icon: Icon(Icons.map),),
            Tab(text: '生物',icon: Icon(Icons.book),),
          ],
        ),
      ),
      body: TabBarView(  //在body里加一个TabBarView
        controller: _tabController,  //也用_tabController作为控制器,这样就能和tabbar对应起来
        children: <Widget>[  //子元素个数应该和tabbar对应起来
          Text("语文"),
          Text("数学"),
          Text("英语"),
          Text("历史"),
          Text("地理"),
          Text("生物"),
        ],
      ),
    );
  }
}

image

二. 底部导航栏

image

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        title: "TEST",
        home: Scaffold(
          appBar: AppBar(title: Text("bottomNavigatorBar")),
          body: Container(
            height: 500,
          ),
          bottomNavigationBar: Demo(),
        ));
  }
}

class Demo extends StatefulWidget {
  @override
  _DemoState createState() => _DemoState();
}

class _DemoState extends State<Demo> {
  int _currentIndex = 1;
  void _onItemTapped(int index) {
    setState(() {
      _currentIndex = index;
    });
  }

  @override
  Widget build(BuildContext context) {
    return BottomNavigationBar(
      onTap: _onItemTapped,
      type: BottomNavigationBarType.fixed,
      currentIndex: _currentIndex,
      items: <BottomNavigationBarItem>[
        BottomNavigationBarItem(
          title: Text("book"),
          icon: Icon(Icons.book),
        ),
        BottomNavigationBarItem(
          title: Text("shop"),
          icon: Icon(Icons.shop),
        ),
        BottomNavigationBarItem(
          title: Text("music"),
          icon: Icon(Icons.queue_music),
        ),
      ],
    );
  }
}

image

三. 下拉按钮组件

image

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "TEST",
      home: Scaffold(
        appBar: AppBar(title: Text("DropdownButDemo")),
        body: Center(
          child: DropdownButDemo(),
        ),
      ),
    );
  }
}

class DropdownButDemo extends StatefulWidget {
  @override
  _DropdownButDemoState createState() => _DropdownButDemoState();
}

class _DropdownButDemoState extends State<DropdownButDemo> with SingleTickerProviderStateMixin {
  int _cureentValue=1;
  List<DropdownMenuItem> dropItemsList(){
    final List<DropdownMenuItem> mitems=List();
    final DropdownMenuItem item1 =DropdownMenuItem(child: Text("book"),value: 1);
    final DropdownMenuItem item2 =DropdownMenuItem(child: Text("shop"),value: 2);
    final DropdownMenuItem item3 =DropdownMenuItem(child: Text("cake"),value: 3);
    final DropdownMenuItem item4 =DropdownMenuItem(child: Text("bank"),value: 4);
    mitems.add(item1);
    mitems.add(item2);
    mitems.add(item3);
    mitems.add(item4);
    return mitems;
  }
  @override
  Widget build(BuildContext context) {
    return DropdownButton(
      value: _cureentValue,
      items: dropItemsList(),//下拉列表
      hint: Text("请下拉"),//提示文本
      iconSize: 48,//图标大小
      elevation: 10,//阴影
      isExpanded: true,//继承父容器的大小
      focusColor: Colors.redAccent, //获得焦点的颜色
      iconEnabledColor: Colors.amber,//按钮可用时的颜色
      iconDisabledColor: Colors.grey,//按钮不可用时的颜色
      icon: Icon(Icons.keyboard_arrow_down),
      style: TextStyle(fontSize: 30,color: Colors.black54,),//字体样式
      isDense:true,
      itemHeight:80,
      autofocus: true,
      onChanged: (T){
        setState((){
          _cureentValue=T;
        });
      }, 
    );
  }
}

image

第五部分打包与发布

Android打包(VScode)

一配置APP图标

图标目录: /android/app/src/main/res/

进入之后你会看到很多mipmap-为前缀命名的文件夹，后边的是像素密度，可以看出图标的分辨率。

mdpi (中) ~160dpi
hdpi （高） ~240dip
xhdpi （超高） ~320dip
xxhdpi （超超高） ~480dip
xxxhdpi （超超超高） ~640dip

将对应像素密度的图片放入对应的文件夹中,图片记得用png格式，记得名字要统一，才能一次性进行配置。

二配置AndroidManifest.xml

这个文件主要用来配置APP的名称、图标和系统权限，所在的目录在:/android/app/src/main/AndroidManifest.xml

android:label="flutter_app"   //配置APP的名称，支持中文
android:icon="@mipmap/ic_launcher" //APP图标的文件名称

三生成keystore

keytool -genkey -v -keystore e:/key.jks -keyalg RSA -keysize 2048 -validity 10000 -alias key

image

在安卓根目录建立key属性文件,并配置

storePassword=<password from previous step>    //输入上一步创建KEY时输入的 密钥库 密码
keyPassword=<password from previous step>    //输入上一步创建KEY时输入的 密钥 密码
keyAlias=key
storeFile=<E:/key.jks>    //key.jks的存放路径

image

四配置android\app\build.gradle

在android{}上面添加如下代码:

def keystorePropertiesFile = rootProject.file("key.properties")
def keystoreProperties = new Properties()
keystoreProperties.load(new FileInputStream(keystorePropertiesFile))

image

把下面内容替换

image

替换成:

signingConfigs {
    release {
        keyAlias keystoreProperties['keyAlias']
        keyPassword keystoreProperties['keyPassword']
        storeFile file(keystoreProperties['storeFile'])
        storePassword keystoreProperties['storePassword']
    }
}
buildTypes {
    release {
        signingConfig signingConfigs.release
    }
}

五生成APK

运行命令:

flutter build apk

flutter框架一文通(一)

第一部分 vscode终端操作快捷键：

第二部分. 框架简介及hello world

一、总体架构

1、总体架构

2、GPU渲染

3.状态控制

4.Flutter理论基础知识

二、写一个hello world程序

第三部分 常用静态组件

一、文字组件 Text("")

1.textAlign （文本对齐）

2. maxLines （最大显示行数）

3. overflow 溢出处理

4. style 文字样式

二、container组件 container() 容器

三. image组件

四. Align组件 //对齐组件

五. Scaffold组件 //(脚手架)

六. AppBar组件 //APP导航条

七. FloatingActionButton //悬浮按钮组件

八. BottomAppBar组件 //底部导航条

九. ButtonBar //按钮条组件

十. NestedScrollView //可嵌套的滚动视图结构

十一. SliverAppBar //可扩展折叠的滚动工具栏

十一. FlexibleSpaceBar组件 //可折叠空间组件

十二. listView组件 列表布局

十三. 网格列表布局

十四. 按钮组件

十五. 水平布局

十六. 垂直布局

十七. Stack组件、Position组件（层叠布局 ）

十八. 圆盘组件

十九. 瓦片组件

二十. 卡片布局

二十一. 分割线组件

二十二. 导航

二十三. 带参数传递的导航

二十四. 异步请求和等待

二十五. 加载静态资源

二十六. Expanded //拓展组件

二十七. sizebox盒模型

二十八. GestureDetector组件(手势监听)

二十九. Dismissible组件(滑动删除)

三十. SnackBar

三十一. 自定义字体

三十二. hero组件 //页面过度动画

三十三. ConstrainedBox //可伸缩盒子

三十四. DecoratedBox //带装饰的盒子

三十五. FittedBox //自适应填充盒模型

三十六. OverflowBox //允许溢出的盒模型

三十七. RotatedBox //允许旋转盒模型

三十八. SizedBox //限定大小的盒模型

三十九. FlatButton //扁平按钮组件

四十. IconButton //图标按钮组件

四十一 OutlineButton //外边线按钮组件

四十二. RawMaterialButton //原始按钮组件

第四部分 常用动态组件

一. tabbar组件 //选项卡

二. 底部导航栏

三. 下拉按钮组件

第五部分 打包与发布

Android打包(VScode)

十九 Android打包(AS)

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第三部分常用静态组件

十二. listView组件列表布局

十七. Stack组件、Position组件（层叠布局）

第四部分常用动态组件

第五部分打包与发布