Flutter入门基础

import ‘dart:html‘;

import ‘package:test/test.dart‘;

import ‘package:base/components/swiper.dart‘;

import ‘package:lib1/lib1.dart‘ show foo;

import ‘package:lib2/lib2.dart‘ hide foo;

import ‘package:lib1/lib1.dart‘;
import ‘package:lib2/lib2.dart‘ as lib2;

import ‘package:greetings/hello.dart‘ deferred as hello;

#name很重要，如果修改了name所有的dart的文件的import前引用的本地的文件啊的包名都需要修改
name: flutterdemo
description: A new Flutter application.
 
dependencies:
  flutter:
    sdk: flutter
 
 #添加依赖packages 
  cupertino_icons: ^0.1.2
  english_words: ^3.1.0
 # image_picker: ^0.4.8
 
dev_dependencies:
  flutter_test:
    sdk: flutter
 
  #启用国际化
  flutter_localizations:
    sdk: flutter
 
flutter:
 
  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true
  # To add assets to your application, add an assets section, like this:
  #添加资源，不单单是图片，images是个和pubspec.yaml配置文件同级的目录，如果不同级，需要添加..
  assets:
        - images/park.jpg
        - images/lake.jpg
        - images/touxiang.jpg
  #  - images/a_dot_burr.jpeg
  #  - images/a_dot_ham.jpeg
   #字体设置
   fonts:
     - family: Schyler
       fonts:
       - asset: fonts/Schyler-Regular.ttf
        - asset: fonts/Schyler-Italic.ttf
           style: italic
     - family: Trajan Pro
       fonts:
      - asset: fonts/TrajanPro.ttf
      - asset: fonts/TrajanPro_Bold.ttf
        weight: 700

debugShowCheckedModeBanner: false

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

  @override
  Widget build(BuildContext context) {
    return new Container(
      color: Colors.red
    );
  }
}

class RandomWords extends StatefulWidget {
  @override
  createState() => new RandomWordsState();
}

class RandomWordsState extends State<RandomWords> {
  @override
  Widget build(BuildContext context) {
    final wordPair = new WordPair.random();
    return (new Text(wordPair.asPascalCase));
  }
}

decoration: new InputDecoration(
                  hintText: ‘input name to search‘,
                  border: InputBorder.none
              )

decoration: BoxDecoration(
                color: Colors.white,
                border: Border.all(color: Colors.green, width: 1.0),
                borderRadius: BorderRadius.circular(4)),

In your `Scaffold`, set `resizeToAvoidBottomPadding` property to `false`.

//...
body: new ListView(
  children: [
    new Image.asset(
      ‘images/lake.jpg‘,
      width: 600.0,
      height: 240.0,
      fit: BoxFit.cover,
    ),
    titleSection,
    buttonSection,
    textSection,
  ],
),
//..

  assets:
        - images/park.jpg
        - images/lake.jpg
        - images/touxiang.jpg

new Container(
  color: Colors.amberAccent,
  width: 300.0,
  height: 300.0,
  child: new FittedBox(
    fit: BoxFit.contain,
    alignment: Alignment.topLeft,
    child: new Container(
      color: Colors.red,
      child: new Text("FittedBox"),
    ),
  ),
)

//获取屏幕宽度的方法
double width = MediaQuery.of(context).size.width;

 @override
  Widget build(BuildContext context) {
    _getConversations();
    return new Scaffold(
      appBar: new AppBar(
        title: new Text(mIsGroup
            ? mConversation.groupBean.groupName
            : mConversation.contactBean.nickName != null
                ? mConversation.contactBean.nickName
                : mConversation.contactBean.pin),
        elevation: 0.5,
        actions: <Widget>[
          new IconButton(
              icon: new Icon(
                mIsGroup ? Icons.group : Icons.person,
                size: 24,
                color: Colors.black54,
              ),
              onPressed: _goContactInfo),
        ],
      ),
      body: new Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: <Widget>[
          new Expanded(
            child: _buildConversations(),
          ),
          Row(
            mainAxisSize: MainAxisSize.max,
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: <Widget>[
              IconButton(icon: Icon(Icons.keyboard_voice), onPressed: null),
              Flexible(
                child: Container(
                    height: 40,
                    margin: EdgeInsets.fromLTRB(10, 6, 10, 6),
                    padding: EdgeInsets.fromLTRB(10, 0, 10, 0),
                    decoration: BoxDecoration(
                      color: Colors.white,
                      border: Border.all(
                        color: Colors.black12,
                        width: 0.5,
                        style: BorderStyle.solid,
                      ),
                      borderRadius: BorderRadius.circular(4),
                    ),
                    child: TextField(
                      decoration: InputDecoration(
                          hintText: ‘输入内容‘, border: InputBorder.none),
                    )),
              ),
              Container(
                margin: EdgeInsets.fromLTRB(0, 0, 10, 0),
                child: IconButton(icon: Icon(Icons.add_circle_outline),onPressed: null,),
              )
            ],
          ),
        ],
      ),
    );
  }

Widget _msgHolder(MessageBean message, BuildContext context) {
    double width = MediaQuery.of(context).size.width;
    double _maxWidth = width * 0.65;
    return Row(
      textDirection: message.from.pin == myInfo.pin?TextDirection.rtl:TextDirection.ltr,
      children: <Widget>[
        CircleAvatar(
          backgroundImage: AssetImage(message.from.avatarUrl == null
              ? "assets/drawable/ava_group.png"
              : message.from.avatarUrl),
        ),
        GestureDetector(
            onLongPress: () {
              _showList(options);
            },
            child: Container(
              constraints: BoxConstraints(
                  minWidth: 0,
                  maxWidth: _maxWidth,
                  minHeight: 0,
                  maxHeight: double.infinity),
              margin: EdgeInsets.fromLTRB(10, 5, 5, 10),
              padding: EdgeInsets.all(8),
              decoration: BoxDecoration(
                color: Colors.green,
                border: Border.all(
                  color: Colors.green,
                  width: 0.5,
                  style: BorderStyle.solid,
                ),
                borderRadius: BorderRadius.circular(4),
              ),
              child: Text(
                _getMessage(message),
                style: TextStyle(color: Colors.white, fontSize: 16),
              ),
            )),
      ],
    );
  }

//SnackBar的显示
Scaffold.of(context).showSnackBar(SnackBar(
     content: Text("长按消息"),
));

showDialog<int>(
        context: context,
        builder: (BuildContext context) {
          return new SimpleDialog(
            children: options.map((value) {
              return new SimpleDialogOption(
                onPressed: () {
                  Navigator.pop(
                      context,
                      options.indexOf(
                          value)); //here passing the index to be return on item selection
                },
                child: new Text(
                  value,
                  style: TextStyle(
                    fontSize: 16,
                  ),
                ), //item value
              );
            }).toList(),
          );
        })

"add","all","alter","and","as","autoincrement","between","case","check","collate","commit","constraint","create","default","deferrable","delete","distinct","drop","else","escape","except","exists","foreign","from","group","having","if","in","index","insert","intersect","into","is","isnull","join","limit","not","notnull","null","on","or","order","primary","references","select","set","table","then","to","transaction","union","unique","update","using","values","when","where"

  audio_recorder: any #录音、播放
  flutter_sound: ^1.1.5#录音
  dropdown_menu: ^1.1.0#下拉菜单
  simple_permissions:#权限获取
  easy_alert:#弹框
  amap_location: any #高德地图
  location: any #gogle位置获取
  barcode_scan 0.0.8#二维码识别qr_mobile_vision: ^0.1.0 #二维码识别 这个不好用
  flutter_screenutil: ^0.3.0#屏幕适配工具类  
  flutter_spinkit: ^2.1.0#加载等待框
  lpinyin: ^1.0.6#汉字转拼音
  shimmer: ^0.0.4#微光效果控件
  qr_flutter: ^1.1.3#二维码生成
  url_launcher: any#启动URL的Flutter插件。支持网络，电话，短信和电子邮件
  datetime_picker_formfield: ^0.1.3#时间选择控件
  flutter_picker: ‘^1.0.0‘#选择器
  common_utils: ‘^1.0.1‘#工具类 时间、日期、日志等
  flutter_html: ‘^0.8.2‘#静态html标记呈现为Flutter小部件
  fluwx: ‘^0.3.0‘#微信支付、分享、登录
  tobias: ‘^ 0.0.6#支付宝
  cupertino_icons: ‘^0.1.2‘#小图标控件
  http: ‘^0.11.3+16‘#网络请求
  html: ‘^0.13.3‘#html解析
  image_picker: ‘^0.4.5‘#图片选择（相册或拍照）
  flutter_webview_plugin: any#webview展示
  fluttertoast: any#toast提示框
  shared_preferences: ‘^0.4.2‘#shared_preferences存储
  transparent_image: ‘^0.1.0‘#透明图片控件
  flutter_swiper : ‘^1.0.2‘#轮播图
  charts_flutter: ‘^0.4.0‘#统计图表
  path_provider: ‘^0.4.1‘#获取系统文件
  cached_network_image: ‘0.4.1‘#加载网络图片并本地缓存
  sqflite: ‘^0.11.0+1‘#sqllite数据库操作
  pull_to_refresh: ‘^1.1.5‘#下拉刷新上拉加载更多
  video_player: ‘0.6.1‘#视频播放
  collection: ‘1.14.11‘#集合操作工具类
  device_info: ‘0.2.1‘#获取手机信息
  flutter_svg: ‘^0.3.2‘#展示svg图标控件
  intl: any#国际化工具类
  connectivity: ‘0.3.1‘#链接网络
  flutter_staggered_grid_view:#瀑布流展示控件
  flutter_file_manager:#文件管理
  loader_search_bar:#导航栏搜索控件
  flutter_image_compress : any#图片压缩
  ota_update : any#App下载更新
  flutter_slidable：#item侧滑控件